How to grow tomatoes in a tunnel?

Tomatoes are the most popular crop cultivated in high tunnels in New York, and they have one of the best economic returns.
High-tunnel tomatoes offer various benefits over field-grown tomatoes:
- Earlier harvests in summer.
- Later harvests in fall.
- Better fruit quality.
- Less foliar disease.
Contents
Structures and trellising
One of the first considerations you must make is whether to produce determinate or indeterminate types of plants. This will affect which type of high tunnel and trellising system you use.
Determinate varieties are slower to mature than indeterminate varieties. They reach a certain height and then stop growing, and tend to produce their harvest in a short window. The Florida-weave method is often used by growers to trellis them horizontally. Determinate varieties are the industry standard for field production in the Northeast, and many of them are early-yielding.

Indeterminate varieties will continue to grow as long as the plants are healthy and not damaged by cold. Most heritage tomato cultivars and greenhouse tomato types are indeterminate. When grown in high tunnels, indeterminate varieties are trained vertically to a single leader by pruning off lateral growth – the secondary shoots known as suckers.
Cultivating indeterminate types necessitates the use of an overhead bracing system to hang the wires that can hold the plant’s weight.
Gothic and hoophouses with straight sides are often the most effective. Hoophouses without straight sidewalls can be used to grow indeterminate varieties in the center, with shorter crops toward the edges.
The advantage of growing indeterminate varieties on a trellis system is that you get a sustained yield over a longer period of time compared with determinate varieties. (With determinate types, you may stretch out harvest by planting multiple kinds with varying days to maturity and/or stagger planting dates.) Nevertheless, trellising indeterminate kinds takes more time and effort than cultivating determinate varieties.
Timing
Most farmers start tunneling tomatoes roughly a month before field tomatoes. For most of central New York, late-April to early-May would be appropriate, with adjustments for warmer conditions downstate and colder conditions in the north, at higher elevations and in other cold pockets.
It’s a good idea to have a backup heat source within the tunnel to lessen the possibility of plant-killing frosts.
Bed preparation
Most farmers use black plastic mulch to warm soil and smother weeds, with drip watering underneath the plastic to keep soil moisture equal.
Before putting plastic, the soil must be tilled and loose. Small tractors or horses can draw tillage equipment in most tunnels, or you can use a hand operated rotary-tine tiller.
Commercial plastic mulch layers need the use of a tractor that is too big for hoophouses and Gothic buildings. In most situations, you’ll have to lay the plastic by hand – not a difficult task with two or three people. Field equipment for laying plastic and drip tape may be accommodated in multi-bay high tunnels.
Fertilization
Test soil in fall to determine fertilizer and lime requirements for crops the following summer. (For additional information on soil testing, see the Cornell Nutrient Analysis Laboratory.)
Soil preparation is a good time to incorporate any needed fertilizers and lime to get them distributed through the root zone. Preplant treatment is particularly crucial for organic growers since it might be difficult to acquire OMRI-approved nutrients that can be administered using drip irrigation systems. Check this CVP article on Nitrogen Fertility Options for Organic High Tunnels for more information.
The big advantage of using drip tape is that you can inject fertilizer into the irrigation water periodically to maintain adequate nutrient levels in the plants. Foliar tissue analysis may be used to monitor nutrient levels and regulate the amount of fertilizer applied via the irrigation system. An injector is beneficial for diluting soluble fertilizers.
Tomatoes produced in high tunnels grow quicker and yield more than field-grown tomatoes, thus they have greater fertilizer needs.
Magnesium is the most common deficiency seen in high-tunnel tomatoes, but is tolerable at low levels. Manganese insufficiency is also widespread. Both may be discovered and rectified prior to yield loss.
Irrigation
Water that is consistent and plentiful is essential for high tunnel tomato production. A deep well or pond is required. Some growers report using a gallon per plant per day during the peak of the season.
Since there is no leaching of the soil profile, any difficulties in the irrigation water will become concentrated within the high tunnel, as opposed to field production.
Water pH, alkalinity, nitrates and pathogen presence should be tested. Some water is alkaline and must be acidified.
Varieties
Farmers in New York have had success with the following kinds, although there are many more that will thrive.
Determinate:
- ‘Mtn. Spring’
- ‘Mtn. Fresh’
- ‘Florida 97’
Indeterminate:
- ‘Geronimo’
- ‘Trust’
- ‘Boa’
Heirloom:
- ‘Cherokee Purple’
- ‘Amish Paste’
- ‘Prudens Purple’
Pests and diseases
One of the most significant advantages of growing in high tunnels is that the plants have better foliar health than in the field. This technique is popular with organic growers because diseases such as early blight and bacterial spot are often eliminated with no fungicide sprays.
Nonetheless, the tunnel atmosphere might favor a few issues that are rare in New York field settings, namely:
- Two-spotted spider mites
- Thrips
- Spotted Wing Drosophila (SWD) in Tomatoes
- Botrytis (Gray mold)
- Leaf Mold in High Tunnel Tomatoes
- Leaf mold
Related Questions
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Can you grow tomatoes in a high tunnel?
High tunnels are used to prolong the growing season throughout the spring and into the autumn. Determinate and indeterminate tomatoes (Lycopersicon esculentum) can be successfully grown in this production system, yielding a potentially profitable “out of season” crop.
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What is the best tomatoes to grow in a Polytunnel?
Vine tomatoes, also known as indeterminate tomatoes, work well in greenhouses and polytunnels.
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How far apart to plant tomatoes in a high tunnel?
Plants are typically planted four feet apart in double rows, with 14 to 16 inches between plants inside the row.
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Can I just dig a hole and plant tomatoes?
You’ve got to dig deep when it comes to tomatoes. The majority of veggies should be planted in a hole the size of the pots they come in. Nevertheless, tomatoes are not one of them. Since they are large, heavy feeders, bury them further into the soil, so that portion of the clipped stem — see below — is buried.