In a greenhouse, you
don't need to wait for the outdoor soil to warm to get a jump start on
your tomatoes. You'll be the envy of your neighborhood enjoying homegrown,
tasty tomatoes long before and after them.
best for your greenhouse? Determinate versus indeterminate
Start with how much room you
have, then choose from one or a combination of the basic cultivars below.
plants form fairly compact bushes with shorter main stems and take
up less space. All their fruit ripens at the same time. They are best
grown in large pots, barrels, raised beds, grow bags. Use 5 gallon or
larger containers. Pots need good drainage holes. Use new potting soil
that drains well. Cage or stake them early on to control. Container plants
require more frequent watering. For good ventilation space them approximately
2 feet apart. Do not to prune or remove side shoots, as these are the
plant's fruiting shoots.
plants grow larger and higher until stopped. Often sprawling, fruit is carried
on the shortish shoots coming off the main stem. Harvest continues over
a longer period. Plant in grow bags*, raised beds, or transplant into the
garden when the soil temperature reaches at least 55 degrees F. Support
with cages or tall stakes. Stakes should be 6-8 ft. tall and at least 1"
x 2". Drive them 6-8" into the ground. Use soft tie or Velcro to train them
Another popular support system is to tie a length of twine from the ceiling
or rafter to the ground for each plant. Tie the bottom end to a stake well
anchored in the ground where the plant is growing. Leave 6-8 inches of slack
on the twine to help spiral and train it upward as it grows.
For good ventilation and best light, space 2-3 feet apart, in a row running
north and south.
Continually pinch out extra side shoots (at junctions of the stem and side
branches) to control overcrowding and increase fruit production. You may
choose to prune lower leaves at the base of plants for better air circulation.
General rule - "less pruning is better than more." Refrain from pruning
leaves covering fruit as they protect the fruit from possible cracking in
the sun. If planted in the ground rotate tomatoes every year to avoid where
potatoes, peppers or eggplant grew before.
and dwarf plants are commonly grown in space-saving smaller pots or
hanging baskets. They are easy to grow and many have high yields. There
are terrific varieties available now for salads and snacking.
for my hanging basket tomato plant is so easy with a Down-Up
Pulley. The Down-Up is also very convenient for my flower hanging basket
Criteria for Choosing
Your favorite outside garden tomatoes probably aren't the best ones for
your greenhouse. Select varieties that have been specially developed
for the greenhouse or that are highly disease resistant. (Territorial
Seed Co., Johnny's Select Seeds, Tomato Growers Supply, Stokes Seeds Co.
all clearly mark recommendations for greenhouse growing and disease resistance
to start with.) As well as space habits, you'll want to take into account
flavor and texture, earliness, vigor, higher yields, if they set fruit without
pollination and how well they do under low light conditions.
Transplanting Seed Starts
Always use fresh, sterile soil to avoid any soil-borne disease–especially
with tomatoes! After the 4th or 5th true leaves have developed on seed starts
you can transplant them into larger containers or beds. Each time you transplant
bury the whole stem below the first set of leaves. The plant will continue
to send out roots from the buried stem and increasingly develop a stronger
General Care Tips
Tomatoes grow best when days are long and they are placed in the sunniest
part of your greenhouse. They do best with day time temperatures of
70 -75°F. and night time temperatures of 60 -70°F. Try to avoid
wide fluctuations in temperature. Growth slows and fruits stop setting
If your plants aren't self-pollinating, when they start to flower
they need your help. In the morning or every other morning, tap lightly
on the yellow blossoms with a long dowel or other easy reach tool.
and clean conditions are essential. Humid, warm conditions can multiply
disease quickly! Keep an air circulation fan going 24 hrs. a day. Provide
consistent means to exhaust hot air out—solar vent openers, exhaust
fan, opening the door & windows.
Water tomatoes using warm or greenhouse temperature water. General
rule—deep water, then let soil dry out before re-watering. Do
not let plants wilt.
Avoid splashing water or dirt on leaves, which might cause disease.
Overwatering can cause fruit to crack.
Tomatoes are heavy feeders. As soon as the first fruit starts to form,
fertilize them regularly with a fertilizer such as Grow
More Terrific Tomato Food18-18-21 or Dyna-Gro
7-9-5. Tomatoes like a high phosphorus level (the middle number on fertilizer)
for fruiting and flowering.
To prevent Tobacco Mosaic Virus, do not smoke cigarettes or bring
tobacco into the greenhouse. (If you are a smoker wash your hands thoroughly
before entering greenhouse.)
Pests & Disease- Whiteflies are the most common pest. Check under
leaves often for signs of tiny flying insects. As a preventive measure
use R3812 Yellow Sticky Traps and R3871 Neem Oil. Blossom-End Rot appears as a round, brown sunken area
on the end of the fruit opposite the stem. Area turns dry and leathery
as fruit ripens. Caused by a calcium deficiency. Treat with a Rot-Stop
product. Check out Charley's pest controls for other pest and disease
make a "grow bag", take a 2 cu.ft. bag of organic soil and punch
a few holes in the bottom for drainage. Slit open the top of the bag. Add
time-release fertilizer if you wish. Plant two tomato starts per bag.