Tomato plants are very easy to grow for beginners and it is very satisfying to pick delicious bright red fruits. However, tomatoes require constant care – you will need to deal with the pest or animals eating tomatoes or identify and treat nutrient deficiencies which account for the yellowing of tomato plant leaves.
Nevertheless, with appropriate care and determination you can harvest 7-8 lb (3-4 kg) tomato fruits per plant. It is easy to achieve if you choose the right variety for your greenhouse and don’t make basic mistakes.
Is it better to grow tomatoes inside or outside greenhouse?
It is possible to grow tomatoes indoors in the pots, container and hanging baskets as well as outdoors from the growing bags and directly in the soil. When growing inside the greenhouse tomato plants are sheltered from strong winds and rain. Also, inside the greenhouse you can achieve the perfect temperature, humidity and air flow.
It is better to grow tomatoes inside greenhouse as you can prevent numerous diseases including late blight. However, if you grow tomato plants in the same spot for a few seasons, they can suffer from soil-borne diseases such as Fusarium wilt, Verticillium wilt and Corky root rot.
It can be easily avoidable if you practice crop rotation and disinfect your greenhouse to get rid of the spores before growing tomatoes. In addition, it is better to grow tomatoes indoors in greenhouse because they don’t tolerate frosts.
What is the best way to grow tomatoes in a greenhouse?
There are three main ways to grow tomatoes in a greenhouse:
1. Directly in the soil – it is an inexpensive and time-saving way to grow tomatoes in a greenhouse. You don’t need to buy containers and if the soil in your greenhouse is well-drained, rich in nutrient and well-aerated you don’t need to buy compost.
Also, if the soil is rich in organic matter, you only need to water even mature plants two times a week. The major drawback is that after a couple of years the build-ups of pests and soil-borne diseases are formed.
2. Pots and containers – it is a popular way to grow tomatoes in greenhouse due to its simplicity. Just buy 2 gallon polythene containers or 10 inches plastic pots and fill them in with peat-based or coir compost.
Although that way you can avoid many diseases originating from the soil, it is more difficult to get the watering right than when growing in the soil. Peat-based composts require more water while coir needs more frequent watering. Overall, with all composts you need to water tomato plants once a day as a minimum.
3. Growing bags – it is the most popular and the best way to grow tomatoes in greenhouse and outdoors. Growing bags are easy to find in any store and buy online, also, they are relatively cheap. Plant 2 to 4 seedlings into each bag and follow the feeding and watering carefully. The most common reason why plants don’t grow is inappropriate watering.
What are the best tomatoes to grow in a greenhouse?
There are countless varieties of tomatoes but you need to choose the best tomatoes for your greenhouse according to your skills. To start with, tomatoes have two growth types:
1. Cordon or Indeterminate also known as vining tomatoes – these are the most common greenhouse tomato varieties. Indeterminate tomato plants continue to grow and set the fruits throughout the growing season until killed by frosts.
Most of the tomato plants are Indeterminate, it is a best option for greenhouse growing if you want steady and slow supply of fruits all year round. However, they tend to ripe slower because they spend energy to grow taller.
Growing Cordon tomato varieties in a greenhouse requires support with the cane, wire or string. You need to remove the side shoots regularly and pinch out the growing point once plant reaches 6 ft.
Here are the examples of Indeterminate tomatoes for greenhouse growing:
- Ailsa Craig
- Big Boy
- Cherry Wonder
- Gardener’s Delight
- Golden Boy
- Golden Sunrise
- San Marzano
- Sweet 100
2. Bush or Determinate tomatoes – these are a good option for greenhouse growing where the space is limited and you want to harvest a lot of fruit within a short amount of time. The main difference from Indeterminate variety is that plants grow to set height – usually 1 to 3ft but can be up to 5ft tall.
Although growing Determinate tomatoes doesn’t require pruning, removing suckers and stopping, the growth can be messy. You still need to use stakes and caging to support branches with heavy fruits. Also, you need to put down black polythene to stop ground fruits from rotting.
In comparison to Cordon tomato varieties, Bush tomatoes do not use energy for growth. Once they reach their height, they set the tomato fruits and begin to ripen them. In some cases fruits can be harvested in 2 weeks.
These are the most common bush/determinate tomato varieties:
- Red Alert
Tomato varieties guide
Apart from the differences in growth, there are tomato fruit varieties which vary in yield, taste and size. There are 5 types of tomato fruits:
- Ordinary Varieties – these are salad tomatoes that are referred to as traditional-sized fruits. The most reliable variety to grow is Moneymaker. If you want to grow the tastiest salad tomatoes, go for Alisa Craig and if you want to harvest fruits early – Harbinger.
- Hybrid Varieties – these are similar to salad tomatoes in appearance but are commonly heavier yielding and are highly resistant to diseases.
- Beefsteak Varieties – these tomatoes are large in size, perfect for sandwiches but rarely used for frying. The most popular Beefsteak tomato varieties to grow in a greenhouse are Dombito and Big Boy.
- Cherry Varieties – these are the smallest tomatoes in size but the sweetest variety of tomato. Although the number of fruits is high, the yield is lower than from salad tomatoes.
- Novelty Varieties – tomatoes are yellow in color, can be stripy and in the shape of plum.
Can you grow tomatoes all year round in a greenhouse?
Grow tomatoes in a greenhouse to enjoy the fruits all year round. Greenhouse shields sensitive tomato plants from frosts, winds and rain. Also, in a greenhouse you can control the environment including temperature, humidity, lighting and air flow.
When should you plant tomatoes in a greenhouse?
If you are growing tomatoes in a heated greenhouse where temperature is at least 50°F (10°C), sow the seeds in propagator in late December and plant out the seedlings in late February or early March. That way you can harvest tomatoes in May-June.
When to plant tomatoes in unheated greenhouse?
If you are going to plant tomatoes in unheated greenhouse (cold greenhouse) where minimum temperature is 28°F (-2°C) do so in late April or early May. When growing tomatoes in unheated greenhouse you need to sow seeds in propagator in early March. That way you can pick the first tomato fruits in unheated greenhouse in July.
How long can a tomato plant live in a greenhouse?
Tomato plants can live for years in a greenhouse, some varieties can live up to 4 years if not affected by soil-borne diseases. Tomatoes are tropical and subtropical perennials so they have perennial life cycle meaning that they live and reproduce for longer than a year.
You don’t come across pests in greenhouse, however, there might be problems with aphids and whiteflies, so even if you don’t see anything just spray the plants once a month to prevent any problems.
How often should you water tomato plants in a greenhouse?
How often you should water tomato plants in a greenhouse depends on the growing medium and age of the plant. Generally water tomato plants regularly to keep the soil constantly moist at all times in a greenhouse.
Not enough water or infrequently results in poor and damaged fruits, on the other hand, too much water or too many times per day leads to rotten roots and stems. Adjust watering according to the growing medium and growth stage.
For example, you need to water a mature tomato plant in a greenhouse 2 or 3 times a day on a hot day in midsummer.