Methods for Home Soilless Vegetable Cultivation and Recommended Green Vegetables Suitable for Growing
In recent years, more and more friends have taken to growing some vegetables at home, which greens up the environment while also yielding truly pollution-free, hazard-free vegetables. Traditional soil-grown vegetables, however, are hard to manage and easily dirty the home environment. Therefore, many friends have begun to choose soilless vegetable cultivation. So what are the methods for home soilless vegetable cultivation? Which green vegetables are suitable for home soilless growing?
I. Vegetable varieties suitable for growing on a home balcony
Vegetable varieties suitable for growing on a home balcony are divided into leafy vegetables and fruiting vegetables.
1. Leafy vegetables
There are two types: those harvested over a long season and those harvested over a short season. Suitable for long-season growing are varieties such as Gynura bicolor (purple-backed gynura), white phoenix vegetable (Gynura divaricata), green leafy kale, leaf beet, western celery, and watercress; a single planting can be harvested successively over a harvest period of as long as 3~6 months.
Suitable for short-season planting are more than 20 kinds of leafy vegetables, including butterhead lettuce, red-leaf lettuce, Lollo Rossa curly-leaf lettuce, Romaine upright lettuce, large fast-growing lettuce, red oakleaf lettuce, green oakleaf lettuce, yellow-heart endive, large-leaf garland chrysanthemum, medium-leaf garland chrysanthemum, red-stemmed leaf beet, yellow-stemmed leaf beet, white-stemmed leaf beet, celery, water celery, green bok choy, purple bok choy, komatsuna, watercress, water spinach, thousand-rib white-stem Kyoto mizuna, golden-thread mustard, and oval-leaf mibuna.
After planting, they can be harvested once in 25~30 days, with a single-plant weight of 150~200 g; the outer leaves can also be peeled off successively for multiple harvests. The colors include red, yellow, dark green, light green, purple and many others, so residents can plant several colors of vegetables in one setup to create landscapes of different styles.
2. Fruiting vegetables
Mainly include tomato, cherry tomato, truss tomato, eggplant, chili pepper, bell pepper, mini cucumber, ornamental squash, Beibei squash, zucchini, melon, and miniature watermelon.
II. Techniques for using balcony vegetable growing setups
(1) Preparing the equipment
Discarded plastic cups with holes poked in the bottom, for raising seedlings. Plastic flower pots or foam plastic boxes (with holes in the bottom) with a tray underneath. Do not use clay pots. 0.5 kg of ceramic gravel and 1-2 kg of perlite (available at building materials stores); vermiculite, peat, and rock wool are all acceptable. Concentrated nutrient solution comes in No. 1 and No. 2 types, which must be diluted and used together. 2 empty plastic bottles (for diluting the nutrient solution).
(2) Raising strong seedlings
When planting, residents can buy ready-grown seedlings themselves, or buy vegetable seeds and sow them in plug trays, then transplant the young seedlings into the “balcony vegetable garden” after they grow.
1. Seed disinfection
Seeds often carry bacteria. To reduce seedling-stage diseases, ensure the vegetable seedlings grow strong, let yourself and your family eat healthy vegetables, and avoid having your efforts come to nothing halfway, it is best to give the seeds a simple disinfection treatment before sowing.
For seeds generally bought from the market, treat them by soaking in warm water. Soak the seeds in hot water at 60 °C for 10~15 min, then lower the water temperature to 30 °C and continue soaking for 3~5 h, then take them out and let them dry.
For seeds with unclean surfaces, that have been stored for a long time, or that have already been contaminated, the chemical soaking method can be used. Commonly, a 100-fold formalin solution is used: first soak the seeds in clean water for 3~5 h, then place them in the chemical solution for 20 min, take them out and rinse them clean with clean water.
2. Sowing
Households with the means should prepare several 72-cell or 128-cell plastic plug trays for raising seedlings, using peat and vermiculite as the substrate at a ratio of 2:1, which both saves seeds and produces sturdy seedlings. Before sowing, water the plug trays thoroughly, sow the dry seeds by broadcasting, cover with 0.8~1.0 cm of substrate after sowing, then cover with a layer of plastic sheeting, mainly to increase temperature and retain moisture.
3. Seedling-stage management
3~5 days after sowing, once the young seedlings emerge, the plastic sheeting can be removed in time; when there is no water vapor on the young seedlings, cover with another 0.5 cm layer of substrate. After emergence, watering should be controlled appropriately to prevent leggy growth, but after 3~4 days, water with a spray bottle, which both lowers the temperature and prevents the seedlings from lacking water due to evaporation. During the seedling-raising period, the temperature should not be too high; the suitable daytime temperature is 20~25 °C and about 10 °C at night. When the seedlings have grown 2~4 true leaves and are 20~25 days old, they can be planted out.
4. Transplanting
When the young seedlings have grown to 3~4 leaves, lift them out, rinse the soil off the roots with water, taking care to damage the roots as little as possible, then transplant them into the holes. After transplanting, the home balcony setup starts operating immediately; set the nutrient solution supply time according to the season. Generally, in summer and autumn, indoor temperatures are high and seedling evaporation is great, so more water is needed: set the timer to start working at 8:00 every morning and stop at 22:00 at night, with each cycle running 20 min and pausing 2 h in between; in winter and spring, indoor temperatures are low and evaporation is small, so less water is needed: adjust the timer to each cycle of 10 min with a 2 h pause.
(3) Management after transplanting
1. Temperature requirements
Because most of the vegetables grown are leafy vegetables, which are semi-cold-tolerant vegetables, during the growing period the plants should be allowed to grow under suitable environmental conditions; during the growing period, the temperature should not be too high; 20~25 °C during the day and 10~12 °C at night are most suitable. A fully enclosed balcony also has a relatively high temperature in winter, so it is less restricted by temperature, and vegetables can basically be planted all year round.
2. Light regulation
The orientation of the balcony determines its light conditions. For a balcony vegetable garden, it is best to choose a south-facing balcony with ample sunlight; a south-facing balcony has full sun, ample sunlight, and good ventilation, making it the most ideal balcony for growing vegetables. Almost all vegetables grow best under full-sun conditions, so generally vegetables can be grown on a south-facing balcony all year round.
3. Nutrient solution management
After emergence, water with diluted nutrient solution 1-2 times a day, with the liquid seeping out into the tray as the standard. Thinning the seedlings: begin thinning when the young seedlings grow 2 leaves, keeping only one seedling per hole and pulling out the excess. Repotting: when the young seedlings have grown 3-5 true leaves, they need to be moved to a larger pot. First spread a layer of soaked ceramic gravel at the bottom of the pot to aid drainage, then spread perlite, transplant the young seedlings together with the substrate into the large pot, and finally cover the perlite with a layer of ceramic gravel. After repotting, water with solution; the first time it should be watered thoroughly, with seepage into the tray as the standard. Watering with solution: leafy vegetables are watered with solution once every 2 days and with water twice a day; fruiting vegetables are not watered with plain water but only with solution, twice a day.
4. Pest and disease control
The home vegetable garden is a soilless cultivation setup, so plants grow vigorously, pests and diseases are mild, and it is clean and hygienic. Below are 2 homemade natural insect-repellent liquids suitable for the home garden. ① Pungent plant extract: take an appropriate amount of basil, scallion, onion, garlic, etc., boil in 500 L of water, let cool, and spray on the plants with a small spray bottle. Used to control pests such as aphids, red spider mites, and ants. ② Wine-vinegar liquid: mix 1 mL of edible vinegar + 1 mL of rice wine + 1 L of water. Edible vinegar diluted 50 times with water can also be sprayed, and can also be mixed with garlic liquid or chili liquid. It has a disease-prevention effect.
III. Harvesting
About 30 days after planting, the upper tender shoots and leaves can be harvested successively; be careful not to harvest too much at once, so as not to affect growth. Examples include Gynura bicolor, large-leaf garland chrysanthemum, and water spinach; for various loose-leaf lettuces and leaf beets, harvest the outer leaves in batches for eating.
Appendix:
Nutrient solution preparation
Preparation before mixing the nutrient solution
① According to the type of crop cultivated, the soilless cultivation method, and the cost, correctly select the nutrient solution formula.
② Select appropriate fertilizers (inorganic salts). Consider both the concentration and proportion of nutrients available in the fertilizer, and choose fertilizers with high solubility, high purity, few impurities, and low price.
③ According to the concentration ratio of each nutrient element in the formula, calculate the amount of each fertilizer separately, then convert it into the actual amount of each fertilizer needed per ton of water or per 10 tons of water.
④ Prepare liquid storage tanks; the nutrient solution is generally prepared as a concentrated mother liquid of 100~1000 times for later use. Each formula requires 2~3 mother liquid tanks. The volume of the mother liquid tanks is preferably 25 or 50 kg; dark, opaque ones are best, and a faucet can be installed at the bottom of the tank for dispensing the mother liquid.
⑤ Select and prepare the water to be used. The water used to prepare the nutrient solution is very important, and the water quality must be selected. Well water, river water, spring water, tap water, and even rainwater can all be used to prepare nutrient solution, but the water used must not contain heavy metal compounds, pathogens, insect eggs, or other toxic pollutants.
Unpurified seawater and industrial wastewater must not be used. Rainwater has a low salt content and is relatively ideal for soilless cultivation, but it often contains trace elements such as copper and zinc, so when preparing the nutrient solution, these can be omitted or added in smaller amounts; tap water contains chlorine and excessive carbonate, so it should be treated before use; well water is groundwater and contains much iron, manganese, calcium, magnesium, sulfur, and NH4+, so the water to be used should be analyzed before preparing the nutrient solution.
Methods for preparing the nutrient solution
① Weigh out each fertilizer separately and place it in a clean container or plastic film bag, or on plastic film spread flat on the ground, for later use.
② When mixing and dissolving fertilizers, strictly pay attention to the order; Ca2+ must be kept separate from SO42- and PO43-, that is, calcium nitrate must not be mixed with fertilizers other than potassium nitrate, such as sulfate types like magnesium sulfate, or monoammonium phosphate, so as to avoid calcium precipitation.
③ The mother liquid can be divided into A, B, or A, B, C storage tanks. Tank A mixes and dissolves calcium nitrate and potassium nitrate, or dissolves the trace elements ferrous sulfate and Na2·EDTA together with calcium nitrate in tank A; tank B mixes and dissolves potassium nitrate, magnesium sulfate, monoammonium phosphate, and other trace elements; in some cases all trace elements are mixed and dissolved in tank C.
④ For the fertilizer dissolution order in tank A, first use warm water to dissolve Na2·EDTA and ferrous sulfate, then dissolve calcium nitrate, adding water while stirring until uniformly dissolved; for tank B, first dissolve magnesium sulfate, then add monoammonium phosphate and potassium nitrate in sequence, add water and stir until completely dissolved; boric acid is dissolved in warm water and then added, after which the remaining trace element fertilizers are added separately. Both tanks A and B are made up to a certain volume with water according to the mother liquid concentration multiple, stirred evenly, and set aside for use.
⑤ When using the nutrient solution, first dissolve the mother liquid from tank A in water, then take the mother liquid from tank B, dilute with water according to the concentration multiple to the standard stock solution, pour it into the supply pool (tank), adjust the pH to the appropriate range, measure the EC value (electrical conductivity), and then use it.
Key points for using the nutrient solution
① Determine the appropriate nutrient solution management concentration. Different crops, different cultivation methods, and different developmental stages and seasons all have different nutrient solution management concentrations. Generally, the nutrient solution concentration for fruiting vegetables is higher than for fast-growing leafy vegetables, and the management concentration required in the mid-to-late growth period is higher than in the early growth period and seedling stage. Taking tomato as an example, the nutrient solution concentration (EC value) during the seedling stage is 1.2~1.8 mS/cm, during the growth period is 1.5~2.0 mS/cm, and in the late growth period it can be raised to 1.8~2.8 mS/cm.
② Master the number of solution supply times and the supply volume well. This must be controlled specifically according to different cultivation methods, different seasons, different crops, and different growth stages; substrate cultivation requires fewer solution supply times, while NFT cultivation requires multiple solution supplies daily. In NFT cultivation, the solution supply volume for fruiting vegetables is 2 liters per minute, while leafy vegetables need only 1 liter.
③ Adjust and replenish the nutrient solution in time. Due to the needs of crop growth, nutrients are continuously selectively absorbed and water is absorbed in large amounts; in addition, evaporation and consumption from the cultivation bed surface, solution supply pipes, and supply pool cause the nutrient solution concentration to change, so it must be checked regularly and adjusted and replenished. Changes in concentration and nutrient status can be detected through nutrient analysis or electrical conductivity (EC value) test results, and then mother liquid is added. When the above tests cannot be carried out, the solution can be replenished according to the amount of water consumed in the supply pool, using the same volume of nutrient solution at the originally determined standard concentration; at the same time, pay attention to regularly replacing the waste nutrient solution to keep the nutrient solution in the pool stable.
④ Frequently detect pH changes and adjust them. During the crop's growth period, the pH of the nutrient solution changes greatly, directly affecting the crop's absorption of nutrients and its growth and development, and also affecting the solubility of mineral salts. Therefore, the pH of the nutrient solution should be frequently detected and adjusted with sulfuric acid and potassium hydroxide respectively; different crops have different pH adaptation ranges, which should be strictly controlled.
⑤ Prevent the occurrence of nutrient imbalance symptoms. As a result of the crop's selective absorption of different ions, as well as changes in pH, nutrient imbalances in the nutrient solution or in the crop body can occur, causing corresponding symptoms that affect the crop's normal growth, development, and yield, and in severe cases leading to failure; therefore, accurate diagnosis and prevention and control are required.
Nutrient solution raw materials
① Macroelements: potassium nitrate 3 g; calcium nitrate 5 g; magnesium sulfate 3 g; ammonium phosphate 2 g; potassium sulfate 1 g; monopotassium phosphate 1 g.
② Trace elements: (use chemical reagents) disodium ethylenediaminetetraacetate 100 mg; ferrous sulfate 75 mg; boric acid 30 mg; manganese sulfate 20 mg; zinc sulfate 5 mg; copper sulfate 1 mg; ammonium molybdate 2 mg.
③ Tap water: 5000 mL (5 kg). Prepare the macroelements and trace elements into solutions separately, then mix them together. The amount of trace elements used is very small and not easy to weigh, so the trace elements can be prepared at an enlarged multiple, and then the amount can be extracted by reducing it by the same multiple. For example, the trace elements can be weighed out at 100 times and made into a solution, then 1% of that solution is extracted, which is the required amount.
The nutrient solution made according to the above formula is slightly acidic, with a pH value of 6.2. The nutrient solution is non-toxic, odorless, clean and hygienic, and can be stored for a long time.
It is suggested to go to a bookstore to buy some, or look up, more professional knowledge, because usually different vegetables also have different formulas to prepare. Of course, there are also general-purpose types.