Head Start
In the United Kingdom, weather has been the main talking point since long before the days of global climate change. It has always been reliably unreliable, even in midsummer. And here in the northeast of the UK, with the sea close on one side, a range of hills (the Pennines) in the middle and the sea at the other side, the weather can be interesting in all seasons
To grow tomatoes and peppers early in the year, the plants need the assistance of a greenhouse and hydroponics to do their best.
Between November and January in the northeast of England the weather is only suitable for the hardiest of plants, tended by the hardiest of growers. After a long winter of eating tasteless grocery store tomatoes that have been flown into the country from hundreds, maybe thousands, of miles away, biting into a ripe-on-the-plant tomato in spring is really appreciated.
But looking forward to a May crop requires a lot of advance work – starting with the germination of seeds the preceding October.
In our house, the airing room beside the hot water tank has the most constant temperature. This gives a faster germination time. Because we are growing by hydroponics, which involves media in an inert form (chemically inactive) we don't have to worry about having soil in close proximity to the drying clothes.Soil is for outside use where the plants are left to fend off the unwanted attention of all the inhabitants they share the soil with. Soil should stay where it belongs, in the garden.
Germinating the seed in the home, whether in October or May, makes sense to me. The seedlings can be given that extra care which would be very expensive to provide outside. Between November and January the growth of most plants slows down or stops. As the days lengthen and the light intensity increases, growth will get progressively stronger, so it follows that the longer you put off planting the better the growth will be. However, if the grower wants that little bit extra, germinating the seed in October or November will mean the young plants will have good root systems ready to plant out as soon as the days start to get longer and growing conditions improve. Commercial growers plant like this to make the most of the good growing period. For the home grower, this will give you a chance to have that much desired sweet red fruit long before your neighbors.
Commercially grown produce can never compete with something you have grown yourself; it is yours, you grew it. The commercial fruit will, more often than not, have been picked before it is fully ripe so that by the time it is on the shelf it will be ripe.
Speaking of seed germination, you can get a rough idea what percentage of your seeds germinate by placing the seeds in a cup of warm water. After a period of time the fertile seeds will sink to the bottom of the cup while the others will float on the water. Do not rush; give the seeds time to take in water. Only use this test on seed that is to be used immediately or seed that has been taken from a ripe fruit.
Peppers need the most heat to germinate and take longer, so the tomatoes and peppers should be in containers of their own. When the peppers are finally placed in the system they take a little longer to settle down as well. I aim for a constant 25 degrees centigrade (77 F)to obtain quick germination, but at these temperatures the seeds can dry out very quickly. To overcome this, a plant container with drainage holes in its base is used; this is filled with Canna Coco and placed in a shallow tray of warm water. The water will be drawn up by capillary action to keep the seeds damp without being so wet that they attract unwanted conditions. Leave them for two days then check their growth. From then on check them every day, keeping the tray full of water. If you wait too long between checks you will have very high, useless plants with yellow leaves on top.
As soon as the seeds show signs of life bring them out into a light, warm area, above 15 degrees (59 F) during the day and not below 14 (57 F) at night). Avoid strong sunlight for the first day or so and feed them with warm water only. Planting seeds like this has the effect of producing beautiful red tomatoes with a fantastic taste.
For the seedling stage use plain water only for the first ten days or so, then take the solution strength up to 10 cF (1.0 EC) as the plants grow finishing with 28 cF (2.8 EC) when the plants are fruiting.
The plants are not placed on NFT (Nutrient Film Technique) trays until they have developed a good rooting system. The NFT system I refer to here is either a channel fitted with a lid (with holes for the plants) or open trays with shallow sides; the bases of both are open at the lower end and have a good slope from the solution input point to the lower open end, The solution input end will be five inches higher in relation to the open end over a distance of seven feet, and the bases of both will be covered with spreader mat. Warm solution (68 degrees Farenheit, 20 C) from a vessel below is pumped up and ejected onto the spreader mat where it spreads out to form a film, runs down and returns to the vessel below. This gives a warm, moist, well-aerated surface for the roots to reach out and spread over. They do this and can form a root mat around 1 to 1 1/2 inches thick after 11 months of growth. The roots forming at the base are in the film solution and the roots that form above them are fed by capillary action from below.
A most important fact here is that ample oxygen is made available to all the roots (above and below). If a pool forms at any point along the length, then the roots at this point will be stressed, leading to diseases or even death by drowning. Good roots are white roots.
The nutrients used are a single balanced mix of hydroponic nutrients called Ionic, a single-liquid mix that is easier to use than two-part systems. Just add a set quantity to a set amount of good water (good water is water with only a few elements in it, and from a source that is clean,) mix well and test its strength with a cF Truncheon or similar meter. Ionic gives good crops and is sold in two forms – "Grow" and "Bloom."
The original hydroponic concentrate mixes are sold in these two forms also, but these are two-part mixes (they can be in solution or dry powder form) called "A" and "B." The reason they are sold as two-part mixes is that some elements in the mix can react with each other to produce another element useless to the plant, so the two mixes are kept apart until diluted in water. Ionic is made in a way that this does not happen.
It is important that the level of the solution in the tank is maintained by adding good water as it falls. Plants can take water and leave the nutrients. If water is not added the solution strength will rise.
To make the solution, the supplier of the nutrient mix will advise the grower on a set quantity of water to be mixed with a set quantity of concentrated nutrient to give a solution at a set strength (cF or EC). This solution can then be used for the main tank. Tell the supplier when you call for a nutrients mix if the water you plan to use will be hard or soft.
After making the main mix, make anther mix of the same quantity and strength as the first. Keep this in another vessel as a top-up solution. When the plants use water or water and nutrient and the level in the tank goes down, top it up to its original level with the top-up solution. The level of the solution in the main tank is now maintained by adding solution from the top up mix until it has all been used. Now the system is cleaned out, the solution for both tanks (the main tank and the top-up tank) is remade (in two separate vessels of course) and the whole procedure is repeated.
The pH is also very important, I aim for 6 to 6.5 and I find that Ionic gives me a reading around this value on the initial mix if it is mixed correctly. However, as the plants take out elements, elements and water or just water, the pH will go up or down depending on the environment around the foliage and the type of growth. This should be checked regularly and maintained by adding pH up or pH down then testing it using a cheap color match unit or a pH Truncheon.
The flower trusses of tomatoes are formed at an early stage of growth, so light is especially important at this stage. Have the light close to the top of the plant, but remember most lamps produce heat as well, so be careful that you do not burn the foliage. For perfection, if you have planted early and the high cost of light is acceptable, then lights controlled by a timer can simulate longer day lengths. Sixteen hours of daylight followed by eight hours of darkness is perfect for the plant's foliage but costly in the winter (the period of darkness is equally as important as the daylight). However, my costs are kept to a minimum and so for this reason I only cover the glass with insulation on the side that gets the cold north wind; I want all the daylight available from the other sides.
Avoid filament lamps, as the heat given off by these can give the grower a great deal of trouble. Stay with fluorescents, low energy or lamps recommended for the purpose from a hydroponic supplier. The color of light is important; plants react more to the violet/blue and orange/red spectrum. The green/yellow portion of light tends to be reflected or passes through the leaf.
The leaves of the tomato plant adjust to the intensity of the light either by producing a larger leaf area in low light or thicker smaller leaves at higher levels. If a tomato plant is exposed to very high light intensity levels it usually positions its leaves vertically, pointing the tips at the light source.
In the interest of cost cutting, the solution is heated to 68 degrees F (20 C) around the roots. Warmer than this can cause problems. This means the air in the greenhouse only needs heating to a minimum of 50 F (10 C).
Still with cost in mind, I insulate the side of the tanks holding the solution and stand them away from the ground on blocks of heat insulation material. Heat from the solution rises around the foliage of the plants and I save the daunting task of trying to take air temperature up 75 F (24 C.)
Recommended temperatures for tomatoes and peppers are a minimum of 16 degrees centigrade (60.8) at night and 25 C (75F) by day, venting at 23C (73.4) – but all that could be expensive!
Hydroponics looks after the roots of the plants by supplying the full range of nutrient (major and trace elements) in the exact quantities and strength required and at a pH which agrees with each plant. It is the grower's responsibility to look after the environment around the foliage.
Les Bridgewood is the author of "Hydroponics: Soilless Gardening Explained." He has been gardening without soil since the early 1970s, and is a regular contributor to several hydroponics publications, including The Growing Edge.
