When soil temperatures inside the high tunnel reach 60°F at 2" depth, it is safe to transplant

For tomato production earliest in the season, row covers, raised beds, drip irrigation, plastic mulch and/or a portable back-up heater may be necessary

 
Five week old tomato seedlings are ready for transplant (Photo Courtesy of Lewis Jett)

Raised beds should be 6-10" high and 24-30" wide

Four foot spacing between raised beds allows five rows in a 20' wide high tunnel

Raised beds can be formed with compact bed shapers or power tillers

After the beds are formed, fertilizer, drip tape, and mulch can be applied.

A bed shaper pulls soil into a raised bed creating a uniform planting surface (Photo courtesy of Kim Williams)

Clear plastic will result in significantly higher soil temperatures than black plastic, however, weeds can germinate and emerge under the clear film

•Organic mulches such as straw, hay or compost can also be used for tomato production in high tunnels

Some organic mulches can actually result in lower soil temperatures than bare soil, so these mulches should be applied after soil temperatures have increased

A typical spacing is 18-24" within rows and 4' between rows. In a 20' X 96' high tunnel, this spacing would accommodate approximately 300 tomato plants

Row covers are permeable to light, water, and air but retain the warmth of the soil after it has been heated by solar radiation

Row covers may come in different thickness or weights

•Row covers are an important component of successful high tunnel tomato production, their use significantly increases the average daily temperature of crops grown under them

Use of row covers generally results in an additional 2-8° F of warmth compared to outside temperatures

Tomato transplants that are properly hardened off can withstand outside temperatures as low as 20°F under the double protection of a row cover inside a high tunnel

Single layer of Row Covers cover tomato plants in Columbia, Missouri (Photo Courtesy of Lewis Jett)

The most effective crop support method is the stake and weave system, but cages may also be used

Tomato plants supported by parallel strings (Photo Courtesy of Lewis Jett)

•Pruning tomatoes refers to the removal of axillary shoots which are commonly called suckers

Remove suckers less than 4" long up to the one below the first flower cluster

Removal of these suckers will not increase yield, but will promote early harvest

From fruit set to harvest, 1-3 quarts of water per plant per day may be required

For example, a high tunnel with 320 plants could require up to 1,100 gallons of water per week

In general, the soil moisture tension for tomatoes should be maintained between 10 and 20 centibars (cb). When measured with a tensiometer, soil moisture tension exceeds 20 cb, irrigation should occur

If required nitrogen can be applied via the drip system two weeks after transplant at a rate of 8-10 lbs/acre

Fresh market tomatoes are harvested at stages ranging from light red to full red, which is also known as vine-ripe

Vine-ripe tomatoes are harvested approximately 2 times per week

The size refers to the number of tomato fruit that will fit into a standard carton: for example, 5X5 tells the buyer that 5 rows of 5 tomatoes are in each layer. This indicates count per box and relative size of the fruit

Tomato boxed and ready for shipment (Photo Courtesy of Lewis Jett)

Name		Fruit Size
Designation	Size	Minimum Inches	Maximum Inches
Maximum Large	4X5	3 15/32	larger
Extra Large	5X5 & 5X6	2 28/32	3 15/32
Large	6X6	2 17/32	2 28/32
Medium	6X7	2 9/32	2 17/32
Small	7X7	2 4/32	2 9/32
Extra Small	7X8	1 28/32	2 4/32