Special Projects – Hoop House Tomatoes

Prepared by ST 10/6/11

Grafted Heirloom tomatoes were trellised with the double leader technique. Each tomato plant’s leaders were pruned except for two which were clipped to its own individual string hanging from the top of the hoop house. This provided adequate airflow for the plants and made it easy to harvest in an efficient manner. We mulched the beds and aisles with hay for weed suppression and to prevent soil from contacting the plants. The outside rows were non grafted indeterminate red slicing tomatoes. We trellised and pruned them using the same method for the grafted tomatoes. Soil moisture sensors were placed in two of the rows to inform us when and how much to water. On average we watered once a week for about an hour. This changed according to the weather. On hot weeks we watered twice a week and during rainy periods we did not water at all. A humidity chamber was built for the newly grafted tomatoes. This consisted of a tent of plastic under the greenhouse table. Cardboard was placed on top of the table to block light out. This created the right environment for the grafts to heal. I learned this method from the first farm I worked at: Blooming Glen Farm.

How to Graft: Grow seedlings of heirloom and rootstock so their stems are about the thickness of a pencil. Cut the top of the root stock off. Cut a downward slit on the rootstock with a matching upward slit on the plant you want to graft. Insert the cuts together and plant into a single pot. Hold plants together with graft clips and mist the cut with a spray bottle. Place under the humidity chamber for 3 to 5 days. Pull the plants out and cut halfway through the base of the heirloom. Twist tie the plants to a skewer for support. Water the base of the plant gently to avoid soil splash. Place the plants back into the humidity chamber for another 3 to 5 days. Take the plants back out and cut all the way through. Now the root stock will be attached to the heirloom. There are some variables to this procedure. Observation of the plant’s health is vital. Slowly introduce the plant back to full sunlight before planting.

Root Stock: Maxifort

Heirloom Tomatoes: Brandywine, Striped German, Paul Robeson, and Black Prince

Non grafted Tomatoes: New Girl

4 beds planted: 2 Outside beds new girl, 2 inner beds with grafted heirlooms (1/2 of bed for each variety)

Single row planting at 18” spacing

Important Dates:

3/4 seedlings were planted

4/22 to 4/27 tomatoes grafted

5/13 tomatoes planted

7/12 first harvest

9/23 last substantial harvest

Yield from 300 row feet of tomatoes:

Grafted Heirloom-1410#

Red-1139#

Worker Hours:

Seeding – 1 hr

Grafting – 16 hrs

Planting – 1.5 hrs

Trellising – 30 hrs

Harvesting – 32 hrs

Clean up – 12 hours