Most Suitable Crops and Varieties

In our case of growing on a small scale either indoors or in a backyard greenhouse, the choice of crop is not fully dependent upon economics, so noncommercial greenhouse crops may be cultured� For example, if you are very fond of some crops that you do not like the quality in supermarket products, grow them yourself hydroponically� Such crops as Asian greens, beans, beets, bok choy (Pac Choi), broccoli, Brussels sprouts, cabbage, carrots, cauliflower, celery, Chinese cabbage, kale, Kohlrabi, leeks, melons, okra, onions, onion sets, peas, radish, spinach, squash, Swiss chard, and zucchini will thrive in hydroponics� However, the choice of substrate is important� For instance, any root crops such as beets, carrots, onions, and radish will need a peatlite or sand substrate as that type of substrate permits the radical or bulb to form uniformly� Do not be afraid to experiment with various substrates and nonconventional crops� After all, part of the exercise is for it to be an enjoyable hobby� In this chapter, most of these nonconventional hydroponic crops are not discussed� Simply select such crops from a reputable seed company catalog� For backyard greenhouses seek varieties that will withstand high temperatures during summer months and others that do well under lower temperatures during winter months� Indoors most varieties will be suitable�

There are two types of arugula: the roquette (rocket) and wild forms� The roquette is the standard salad arugula� The wild forms tend to be more pungent in flavor� “Astro” is a heat-tolerant variety of roquette form� “Sylvetta” also known as “wild rocket” is slower growing with a more pungent flavor� All grow well in all types of hydroponic culture�

This Chinese cabbage is also known as Pak Choi, Pac Choi, and Bok Choi� Most are green, but a few have purple leaves and red/green stems� Some varieties are tall, while others are more compact� My preference for growing hydroponically is the dwarf varieties as they will not lodge (fall over) or require large spacing and do well in plant towers (Figure 22�1), nutrient film technique (NFT), and raft culture systems� The smaller varieties can be spaced similar to lettuce (four plants/ sq ft)� Some of the best varieties we have found to do well under hot conditions include: Green Fortune, Red Choi, and Takuchoy (Takuchoi)� These are all dwarf in form� Other low-profile varieties (4-6″ tall) include the following: “F1 Hybrid Dwarf Bok Choy” that tolerates high heat and cold can be harvested within 45 days from sowing; “Dwarf Bok Choy” matures in 40 days; “Extra Dwarf Bok

Choy” is only about 2″ tall and is ready in 30 days; and “Huo Guo Chai” is good for stir fry and soups� These varieties are available from Tainong Seeds, Inc� (www�tainongseeds�com)�

Iceberg lettuce should not be grown for several reasons� Firstly, it has very low nutritional value compared to bibb or leafy lettuces� Secondly, it does not form a tight head under high temperatures that normally would be encountered in a backyard greenhouse� There are many choices of varieties of leaf lettuce, oakleaf, Lollo Rossa, butterhead (Bibb), and Romaine/Cos� Leafy varieties include the green varieties “Black Seeded Simpson,” “Domineer,” “Malice,” “Frizella,” “Waldmann’s Dark Green” and red varieties “Red Sails,” and “New Red Fire�” Red oakleaf lettuces are “Navarra,” “Oscarde,” “Red Salad Bowl,” “Ferrari,” and “Aruba�” Some green oakleaf lettuces available are “Cocarde,” “Tango,” and “Green Salad Bowl�” Lollo Rossa types comprise of “Dark Red Lollo Rossa,” “Locarno,” “Revolution,” and “Soltero” to mention a few� Butterhead or bibb lettuces that I have grown with NFT and raft cultures include “Buttercrunch,” “Charles,” “Cortina,” “Deci-Minor,” “Milou,” “Ostinata,” “Rex,” “Salina,” and “Vegas�” I have found that “Rex” is one of the best varieties for the raft and NFT systems under high temperatures as it bolts (goes to seed) slowly� Romaine or Cos varieties need cooler temperatures, and should hence be planted during the cooler seasons, otherwise they may bolt quickly under high temperatures� You may plant them under most temperatures if you do not require a crisp head formation� They will be more like a leafy lettuce under higher temperatures� Varieties include “Green Forest,” “Parris Island,” “Outredgeous” (red), and “Rouge D’Hiver” (red)� Several fine leaf lettuces that are becoming popular are “Multi Red 1, 2, 3” and “Multi Green 1, 2, and 3�”

There are numerous others to choose from presented in seed catalogs� The preceding are varieties that I have had success with growing hydroponically�

These premixed blends of color and texture of lettuces are for mesclun mixes� The varieties in each mix are selected to have similar growth rates to allow uniform size at harvest� You may also create your own lettuce salad mixes� Simply, purchase the varieties you wish and mix them in a container before sowing them� You may mix different ratios of these varieties� For example, if emphasis is on red varieties use a larger portion of the seeds as red varieties�

Johnny’s Selected Seeds (www�johnnyseeds�com) offers a number of pre-mixed lettuce blends� Their “Encore Lettuce Mix” has Green Oakleaf, Red Oakleaf, Green Romaine, Red Romaine, Lollo Rossa, Redleaf, and Bibb lettuces� The “Allstar Gourmet Lettuce Mix” combines Green Oakleaf, Red Oakleaf, Green Romaine, Red Romaine, Lollo Rossa, and Redleaf lettuces in a balance of color and texture proportions� The “Five Star Greenhouse Lettuce Mix” is a blend of downy mildew-resistant varieties for indoor culture� The “Wildfire Lettuce Mix” was created for high color contrast of the red varieties paired with green varieties�

These should be seeded in beds using a peatlite substrate� Shake the package before sowing to mix the seeds evenly� Sprinkle about 60 seeds per foot in a 2-4″ wide band� Cover lightly with about 1 8″ of peatlite or vermiculite medium� Keep the bed moistened with raw water until germination occurs and the seedlings reach about 1″ high� Thereafter, water every day with a half-strength nutrient solution using a watering can� Within 3 weeks, harvest by clipping the tops with a scissors� Do not cut lower than 1″ from the plant base to allow re-growth� Several, up to three, harvests may be made if cared for properly�

There are many varieties of basils; the choice depends upon what you wish to use it for and what kind of flavor you want� The most common is the classic Italian sweet basil (Genovese)� This variety is tall (24-30″) with large leaves up to 3″ long� It takes about 68 days to maturity, but may be harvested after 3 weeks from sowing� The seeds germinate in 5-10 days�

Basils need to be cut often, usually every few weeks, to keep the plants from flowering and going woody� The first cut should be made above the second node leaving at least two sets of side shoots below (Figures 22�2 and 22�3)� That will train the plant to branch often so that it becomes very bushy� The next cut should be these side shoots again as they reach the second node� Harvest above the second node permitting four more side shoots to form� This constant pruning at this stage of side shoot development will keep the plants vegetative and reduce flowering� When flowers form immediately, pinch them to prevent the plant from getting generative and becoming woody� Eventually, after about 3 months, it is best to replace the plants� Start seedlings in a peatlite substrate or in Oasis or rockwool cubes depending upon the hydroponic system you are using� If in raft culture or NFT, it is best to use 1″ rockwool cubes� If in a bed of peatlite mix sow the basil in a peatlite mix in 72-celled compact trays� Sow seeds 3 weeks prior to the transplanting date at which you remove the old plants�

It is best to use Fusarium-resistant varieties for indoor or greenhouse culture� Several Italian basils with disease resistance are “Aroma 2” and “Nufar�” These seeds are available as “organic” as well as pelleted (clay coating) of inert National Organic Program compliant materials (Figure 22�4)� Pelleted seeds are coated with a clay-base material that enables easier sowing and at the same time maintains moisture around the seed to prevent desiccation during germination�

Asian or Thai basils are used as a condiment in Thai and Vietnamese dishes� Several varieties are “cinnamon” and “sweet Thai” basils� These take about 64 days from seeding to maturity� Their leaves at 2″ are somewhat smaller than Italian basils� Often the blooms of these basils are used for flower bouquets� Cinnamon grows to 26-30″ tall while the sweet Thai is shorter at 12-18″� Care of the plants and the hydroponic systems are the same as for the Italian basils� There are citrus basils, “Lime” and “Mrs� Burns Lemon,” that have a distinct citrus flavor and aroma� They are used to add a citrus flavor to fish and salads� The leaves are about 2″ long and the

plants grow from 20″ to 24″ tall taking 60 days to maturity� Once again grow and train them as for Italian basils�

Fine leaf or Greek basils are used like regular basil in pesto, soup, stuffing, or any vegetable dish, especially beans, peppers, eggplants, and tomatoes� Their flavor is stronger than Italian basils� “Spicy Bush” basil matures in 70 days with 1″ long leaves� Plants can be grown in pots or beds reaching a height of 8-14″� “Pistou” basil is a compact form of basil ideal for container growing� Leaves reach ½″ long with a height of 6-8″�

Purple basils may be used for garnishes and cut flowers� Some varieties are “Dark Opal,” “Red Rubin,” and “Purple Ruffles�” These require about 80 days to maturity� Leaves are about 3″ long and the plant height reaches 16-24″� These purple basils normally contain up to 20% of green or variegated plants� I have grown them successfully in a peatlite bed as well as in NFT hydroponic systems� They will grow in plant towers, but the taller basils may lean over as they mature, causing shading of the plants below� As a result, it is not the best hydroponic system for basils apart from the low-profile varieties� Plant training and harvesting procedures are the same for all basils� Of course, if you want them to flower they must not be cut back as often as if they are to be used for the leaves and stems only�

Most herbs grow well in peatlite beds and in plant towers using coco coir, mixes of peatlite with perlite or rice hulls, and in perlite by itself� Select more compact forms or those that hang down in the plant towers� Some of the most successful types that

I have grown in plant towers with a perlite substrate include chervil, regular chives, garlic chives, cilantro, dill, fennel, lavender, marjoram, mint, oregano, moss parsley, Italian (flat leaf) parsley, rosemary, sage, savory, and thyme�

“Vertissimo” chervil is slow-bolting and vigorous, and is hence good for greenhouse culture� It has a mild, sweet anise flavor and is popular for salads, micro greens, and garnishing� It takes about 2 months to first cutting� Chervil may be harvested for 2-3 months depending upon the weather� Under hot, summer conditions, it should be replaced after 3-4 months from sowing� The first harvest can be as early as when the plants reach about 4″ in height� Permit them to re-grow 4″ or taller before the next cutting� Chervil germinates in 10-14 days�

There are two types of chives: the “Fine Leaf” and the “Chinese Leeks/Garlic Chives�” The chives have a mild onion flavor� The glove-shaped flowers may be used as an edible garnish� “Fine Leaf” chives have slender round leaves and are for fresh use� They take 75-85 days from sowing to first harvest� If properly maintained by frequent harvests, thereafter they will continue producing for almost a year� “Chinese Leeks/ Garlic Chives” have thin flat leaves with a delicate garlic flavor� The flowers are edible and are used in bouquets� They take about 90 days to mature from sowing; however, you may begin cutting the leaves once they reach 6-8″ in length, but do not cut them back more than 3″ from the plant base (crown)� This length allows sufficient photosynthetic leaf area for the plant to quickly re-grow� Chives germinate within 7-14 days�

Cilantro/coriander is very easy to grow in plant towers in bunches at the corners of the pots� All herbs that are directly sown in the plant towers should have 8-10 seeds sown at each corner to obtain a “bunch” of plants� Cilantro can also be grown as a micro green� The foliage of this plant is known as “cilantro,” while the edible seed is “coriander�” Some popular varieties are “Calypso” and “Santo” that grow to leaf harvest within 50-55 days from sowing reaching 12-18″ tall� These varieties are slow to bolt so are ideal for greenhouse hydroponic culture� They may be grown using plant towers or NFT� Cilantro seeds are actually fruits that contain two or more seeds� “Santo” seeds are available as “monogerms” whereby the seeds (fruit) have been split to get individual seeds permitting more precise planting� Also, the split seeds germinate faster than the regular fruit seeds� Sow six to eight seeds directly in the plant towers allowing 7-10 days for germination� If you cut the cilantro early when it reaches about 8-10″, two to three harvests will be possible before it goes to seed (bolts)� Change the crop about every 3-4 months�

Dill may be grown for the foliage only or for the flowers� They take 40-55 days for first leaf harvest as shown in Figure 22�5, or 85-110 days for seed� Dill takes 7-21 days for germination� “Bouquet” grows to 38-42″ at maturity� However, to cut it for leaves in cooking begin harvesting when the plants reach 8″ tall� Cut it back lightly allowing about 4-5″ growth for regeneration� If you keep it cut back lightly each time it re-grows to 8-10″ tall, the plant will last for about 3-4 months� For use in making pickles, and so on, where the flower is needed, only one harvest is possible as the plant has matured at that time� “Fernleaf” is dwarf dill slow to bolt� It reaches 26-32″ in height� It has dark blue-green foliage and is best for growing in containers or in the plant towers� “Verling” dill is better for ornamental or cut-flower use� The leaves may be used for garnishing and culinary purposes� The plant grows to about 42-48″� Sow 10-12 seeds in the corners of the plant towers�

Fennel has feathery foliage with a sweet flavor used in salads, Cole slaw, and dressings� There are “Bronze” and “Bronze and Green” varieties� The seeds germinate within 7-14 days and mature within 50-60 days to a height of 24-36″� Sow four to six seeds per pot corner in the plant towers� These also should be harvested numerous times from when they reach about 8″ in height� Keeping them trimmed will permit three to four harvests between cropping over a 3-4 month period�

Lavender prefers a well-drained substrate and so does well in perlite in the plant towers� It will grow for a year between crop changes� Germination occurs within 14-21 days growing to a plant height of 12-30″� Sow four to six seeds per plant tower pot corner or start them in Oasis cubes and transplant one cube with four to six seedlings after 3-4 weeks� It can be harvested for the foliage or the purple flowers for fragrance� It takes 100-110 days from seed to flower� If harvested for foliage begin once the plants reach 8″ in height and continue harvesting as it re-grows to about 10-12″� As the plants age allow longer growth between the crown and cutting

height during harvesting to avoid dieback that will eventually occur within the lower part of the plants�

“Sweet marjoram” has an aroma similar to oregano, but sweeter and more balsam-like� It will grow for a year between crop changes providing it is cut back on a frequent basis of every 3 weeks or so� It germinates within 7-14 days and matures within 80-95 days to a height of 8-24″� In the plant towers, directly sow about 10-12 seeds per pot corner� As the plants grow they will hang down as if in hanging baskets� This is similar for most of the herbs grown in plant towers� Begin initial harvesting as the plants reach about 8″ tall� Cut them back lightly to within 3-4″ from their base� Do not allow them to flower in order to keep them succulent� When harvesting any of these herbs that hang down, carefully pull them apart into a bunch with your hand and make one clean cut straight across the top of the bunch keeping at least 4″ of plant remaining� As the plants progressively re-grow allow more of the base to remain to avoid cutting into old material that will eventually suffer some die back�

Spearmint is the most common mint grown for culinary use� Mint seeds are very small so sow, about 15-20 seeds per pot corner� Germination is within 10-14 days� The plants will reach 18-36″ as they mature and hang down in the pots� They mature within 60 days for the first harvest when they reach about 10″ long� As with other herbs in the plant towers, they will hang down and need to be separated by hand during harvesting� These plants will easily re-grow for up to a year providing they are correctly cut back frequently, within 3-week intervals�

“Greek oregano” is used in Italian and Greek cooking� It germinates within 7-14 days and will grow to 8-24″ over 80-90 days� Begin harvesting when it reaches 8″ in length� With time it hangs down and like many of these herbs will completely cover the entire pots of the plant tower (Figure 22�6)� Sow about 8-10 seeds per pot corner� Begin harvesting on a regular 3-week period once the plants reach 8″ in length� These plants will continue growing for a year between crop changes�

There are two types of parsleys: curled parsley (“Forest Green”) and Italian or flat-leaf parsley (“Giant of Italy”)� “Forest Green” is a standard variety of curled or moss parsley� Parsley is slow germinating at 14-30 days� Directly sow 10-12 seeds per pot corner� Parsleys will grow between 16″ and 18″ in height within 75 days� As with other herbs begin harvesting as the plants reach 6″ tall� As they continue maturing, they will hang down in the pots to form a mass of plants� Harvest them regularly every few weeks to keep them succulent� Do not cut back the plants to less than 4-5″ during cropping� They will easily last a year between crop changes� Periodically as dieback occurs in the plant bunches remove the dead plant material to prevent fungal infection� This is also very important with chives� Italian or flat-leaf parsleys have large dark green leaves and strong upright stems initially until they begin to hang down in the plant towers as they mature� If you grow these herbs in pots or beds, they will not lodge as they do in the plant towers�

Rosemary germination is slow and irregular at low rates� To overcome this use “primed” seeds that give faster and more uniform germination than raw seeds� Use primed seeds within 6 months of purchase as viability falls with time� Germination occurs within 2-3 weeks and plants mature between 120 and 180 days� You may start cutting the tips after 80-100 days� It is best to sow (about four seeds) in Oasis cubes and transplant to the plant towers after 4-5 weeks� Starting the seedlings in

Oasis cubes has the advantages of regulating watering carefully and at the time of transplanting allowing the placement of several cubes in a pot corner when only a few seeds germinate in some of the cubes� Rosemary will grow for a year in the plant towers between crop changes� By that time, a lot of woody stems with the dieback of leaves occur in the center of the plants reducing the harvestable succulent shoots� With continued growth, the plants hang down and will have to be cut further out from their base by trimming off the outer 4-5″ of shoot growth�

“Common Sage” has a wide variety of culinary uses� Its dusty green leaves are used in dressings, sauces, and teas and is a great source for dried floral wreaths� Sow six to eight seeds directly in the pot corners� Germination is within 1-3 weeks and maturity at 80-90 days� Start harvesting the shoots when the plants reach 6″ in length� Sage will hang down in the plant towers, so frequent cutting every few weeks is important to keep the plants succulent� Sage can easily last up to a year between crop changes� It will grow from 16″ to 30″ long as it cascades down covering the entire plant tower (if the tower is only sage)�

Summer or “Common Savory” with its peppery flavor adds spice to dishes� Sow six to eight seeds directly into the pot corners with germination taking 7-14 days� Plants will grow between 10″ and 18″ within 60-70 days� Start harvesting the shoots when the plants reach 8″ in height� Savory is similar to chervil and will need crop changes every 3 months�

“Summer Thyme” is used in many culinary dishes� It germinates in 3-4 weeks and is ready for first harvest after 3 months� Since it is slow growing, it is best to sow 15-20 seeds in Oasis or rockwool cubes� Transplant to the towers after 5-6 weeks� Sowing in cubes enables the selection and combination of cubes in the plant corners to get adequate plant numbers per pot corner (usually at least 8-10 plants per corner)� The plant height is 6-12″ as it hangs down in the towers� Thyme will be productive for about 6-8 months before changing the crop� Start harvesting the shoots when they reach at least 6-8″ in length� Grasp a handful as a bunch and cut straight across with a scissors leaving at least 4″ of growth remaining (Figure 22�7)� As the plants mature, they will start to dieback at the center so the shoot tips must be harvested

repeatedly further from the plant base leaving from 6″ to 8″ for re-growth� This will keep them more succulent by not cutting them back hard� If they are cut back hard the plants may die�

When planting herbs in plant towers, it is important as to the position in the tower where specific herbs should be located� Locate upright herbs such as basils and chives in the top pots and the others that hang down in the middle and lower pots� Try to keep the ones that cascade most near the bottom of the plant tower so that they do not grow over the others below� A typical arrangement of a plant tower for growing many of these herbs may be starting from the top pot down: chives, basil (it is preferable to grow basil in NFT to avoid the lodging), parsley, chervil, cilantro, dill, fennel, thyme, lavender, sage, rosemary, marjoram, and mint� Since the number of pots per plant tower should not exceed 10, make up at least two plant towers or combine several herbs in the same pot of the tower�

In summary, when growing herbs in plant towers the plants will hang down as if they were in a hanging basket� This form of growth will cause competition for light for the adjacent pot immediately below� To assist in reducing this shading keep plants pruned from an early stage as soon as they reach 6-8″ in length� Frequent cutting back of the outer shoots will keep the plant succulent and reduce dieback in the center of the plant� When harvesting hanging herbs (as most are) take a handful and bunch them together as you cut the shoots back using a scissors� Be careful to always, especially during the first harvest, allow at least 4″ of growth between the cut and the crown (base) of the plant� Cutting back too hard will retard re-growth and even possibly kill the plants� As the plants mature, continue to cut further away from the crown to avoid cutting into the woody older growth� Do this by cutting a maximum of 4-5″ of the shoot growth at any given time� Do not allow the plants to flower unless their use is for floral arrangements and not culinary additives�

Sow lavender, rosemary, and thyme in Oasis or rockwool cubes and transplant to the plant towers after about 5-6 weeks when the seedlings reach about 3″ tall� Sow the others directly into the substrate of the plant tower pot corners� After sowing, either add about ¼″ layer of medium on top of the seeds or mix the top of the medium so that the seeds go below the surface� It is important to pre-soak the substrate with raw water prior to sowing the seeds and again after sowing� Thereafter, for the first 3-4 days, manually water the pots with raw water using a watering can� Check to be sure that all drip lines are working and that the medium remains moist between irrigation cycles�

Some herbs, such as chives, lavender, marjoram, mint, oregano, parsleys, rosemary, and sage, will continue growing well for a year provided they are frequently cut back as soon as the shoot tips grow 4-5″ from the previous harvest� Replace thyme after 6 months, and basils, chervil, cilantro, dill, fennel, and savory after 3-4 months� Whenever the plants become dry in the interior of the bunch getting woody, not rapidly forming new succulent growth, they should be changed� Be careful with the drip lines: If the stakes become plugged with plant growth then the solution will be reduced causing wilting and dieback of the plants� Similarly, if too much solution is applied and it runs out of the pots moistening the plants, dieback will also occur (Figure 22�8)� This dead plant material has to be removed to prevent disease infection� Periodically, prune out dead plant material, especially for chives

and parsley to allow rejuvenation of the remaining shoots from the crown and to reduce the risk of diseases (Figure 22�9)�

Several photos are presented to demonstrate the type of growth expected with herbs in plant towers (Figures 22�10 and 22�11)�

Vine crops include eggplants, European cucumbers, peppers, and tomatoes that are all trained vertically by strings and support wires above� While many staking (indeterminate) varieties may be selected for growing indoors or in greenhouses, it is best to stay with the special greenhouse varieties as they have proven to perform best under controlled environments� Nonetheless, if there are certain heirlooms that you wish to culture for their flavorful fruit, regardless whether they are staking or

bush (determinate) plants they will grow indoors with hydroponic culture� The main reason for using staking varieties is to better utilize the vertical space in the growing area�

Greenhouse eggplants are becoming very popular in the market due to their smaller size and firm fruit with few seeds and fleshy interior� There are now special greenhouse staking varieties available� High-yielding purple varieties include “Taurus,” “Berinda,” and “Agora�” “Taurus” and “Berinda” are DeRuiter seeds and “Agora” from Rogers NK� “Tango” is a white eggplant with a cylindrical fruit 7″ long by 2″ in diameter� This is also a DeRuiter seed� There are many bush forms of different colors and shapes� These may be grown hydroponically, but they will not yield as heavily

as the staking ones� Several I have grown in plant towers are “Hansel” (purple) and “Fairy Tale” (purple and white stripes)� These are compact bush types about 2 ft tall� They mature in 65 days compared to the greenhouse staking ones that take about 11 weeks�

These are the “Long English” seedless (parthenocarpic), burpless types that are shrink wrapped in supermarkets to prevent moisture loss due to their thin skin� There are many varieties; the choice depends largely on your environmental conditions such as light intensity, temperature, and relative humidity� Most are now all female (gynoecious) plants� Varieties I have found to be best for humid conditions that are resistant

to Powdery Mildew fungus include “Dominica,” “Logica,” “Marillo,” “Camaro,” “Fidelio,” and “Flamingo�” Other popular cultivars include “Bologna,” “Corona,” “Discover,” “Jessica,” “LeReine,” “Optima,” “Pandorex,” “Sandra,” “Santo,” and “Toska 70�” Try a number of different varieties under your specific conditions to determine those most resistant to diseases and most productive� These cucumbers take about 10-12 weeks from sowing to first harvest� In some areas two crops per year are feasible; however, from my experience in many locations, I prefer to change crops every 3-4 months to obtain high yields�

These are similar to the European cucumbers in that they produce seedless fruits with thin skins� A number of varieties in my experience that are highly productive and tolerant to powdery mildew are “Jawell,” “Katrina,” “Nimmer,” “Sarig,” “Suzan,” and “Manar�” “Manar” is a DeRuiter variety that is most resistant to powdery mildew� Both European and BA cucumber seeds germinate within a few days of sowing� Harvest fruits when the fruit is between 1�25″ and 1�75″ in diameter and from 5″ to 6″ long� The first harvest is usually a week or so earlier than the European cucumbers� Grow at least four crops per year as they cannot be trained the way European cucumber plants are when they reach the support wire� Allow them to grow over the support wire and hang down without cutting the main stem�

All peppers will grow well hydroponically regardless of whether they are greenhouse or field varieties� However, once again when growing indoors or in a greenhouse use staking varieties in order to use the growing area most efficiently� If you have some favorite varieties that you wish to grow, certainly use them, even if not greenhouse cultivars� With bush varieties, the cropping period will be shorter than the staking greenhouse varieties� Most garden varieties take from 55 to 75 days from sowing to first harvest, whereas the greenhouse ones take about twice that time, normally close to 4 months from sowing� The bush varieties will produce up to several months, so with these cultivars, three crops per year may be rotated, whereas the greenhouse plants yield for 7 months or longer, and so are a single crop per year�

The most popular greenhouse peppers are the sweet bell peppers� Now a few hot peppers and mini bell peppers are entering the market� Bell cultivars are yellow, orange, and red in color� There are many varieties available from various seed houses� Some varieties that I have found very productive include “Bachata,” “Cigales,” “Lesley,” “Samantha,” and “Striker�” These are yellow fruits, but unfortunately “Samantha” and “Lesley” are no longer available� The seed companies keep on changing varieties, introducing new ones every year, so you must try new cultivars as they are developed� Orange varieties include “Arancia,” “Magno,” “Orange Glory,” “Paramo,” and “Sympathy�” Red cultivars include “Fantasy,” “Jumilla,” and “Zamboni�” Most of these varieties produce blocky fruits weighing from 200 to 240 g (7-8�5 oz)�

Some hot varieties are “Fireflame” and “Habanero Red�” “Habanero Red” is a bush (determinate) variety that is relatively hot having a scale of 400,000 Scoville units� The fruit size of “Habanero Red” is 2″ wide by ¾″ long, whereas “Fireflame” is an indeterminate Cayenne type with fruit length up to 6″�

Several mini, small bell, sweet peppers are “Tinkerbell Red” and “Tinkerbell Yellow�” These mature in 60 days and produce fruits 1�5″ × 1�5″ (3�7 cm × 3�7 cm)�

Tomatoes fall into a number of types such as beefsteak, tomato-on-vine (TOV), cherry, grape, plum, cocktail, roma, and heirloom� Any of these can be grown hydroponically indoors or in greenhouses, so the choice depends upon personal likes for the specific fruit� All of the varieties exemplified are indeterminate (staking)�

Beefsteak tomatoes are the more traditional types of large fruits weighing from 7 to 9 oz (200-250 g)� Common greenhouse varieties are “Beverly,” “Blitz,” “Caiman,” “Caramba,” “Caruso,” “Dombito,” “Geronimo,” “Match,” “Matrix,” “Quest,” “Rapsodie,” “Style,” and “Trust�” “Blitz” and “Match” are no longer available�

A cluster or TOV tomatoes now make up about 70% of the fresh market� The fruit weight of TOV varieties is between 3 and 5 oz (90-150 g)� These are the tomatoes packaged as trusses of fruit, but they can be harvested individually if grown for personal use� Popular red varieties include “Ambiance,” “Brillant,” “Clarance,” “Clermon,” “Endeavour,” “Grandela,” “Success,” “Tradiro,” and “Tricia�” “Lacarno” is yellow and “Orangaro” (“DRK 920”) is orange in color�

TABLE 22.1 Recommended Vegetable Varieties for Hydroponic Culture

Cherry tomatoes have a small fruit size weighing less than 0�5 to 0�9 oz (15-25 g)� They also are marketed attached to their flower clusters; however, for backyard growing select the ripest individual fruit during harvesting to get the best flavor� Some popular varieties include “Conchita” (red), “Favorita” (red), “Juanita” (red), “Goldita” (yellow), and “Zebrino” (green stripes)�

Grape/plum varieties of similar fruit size to cherry tomatoes are “Dasher,” “Flavorino,” and “Picolino,” which are red; “Goldino,” which is yellow; and “Orangino,” which is orange�

“Red Delight,” a cocktail variety, has a fruit size from 1 to 2�6 oz (30-75 g)� This is similar to the Roma varieties that include “Granadero,” “Naram,” and “Savantas,” all of which are red and weigh between 3�5 and 5�3 oz (100-150 g)�

Heirloom tomatoes that are indeterminate and therefore suited for greenhouse or indoor hydroponic culture include “Brandywine” (red), “Striped Green Zebra” (green stripes), and “Yellow Pear” (small pear-shaped fruit of ¾–1 oz or 20-30 g)�

Most of these tomatoes take 70-80 days from sowing to first harvest� They will also grow for the entire year as a single crop, but if they lose vigor and yields decline they can be replaced once to obtain two crops per year�

Table 22�1 summarizes varieties suitable for indoor hydroponic culture� Of course, as mentioned earlier, you may grow most varieties of vegetable crops hydroponically�

TABLE 22.1 (Continued) Recommended Vegetable Varieties for Hydroponic Culture