When should you plant your garden tomatoes? Every year the seedlings arrive in nurseries and big-box stores by the middle of February. These tomatoes have been grown in a hothouse and do not like cold feet. They also prefer warm leaves, so don't put them out too early.
Wait until the soil temperature is at least 60°F during the day. Even without measuring I can tell that my soil is not close to that as the water coming out of my well is very cold. You can purchase a soil thermometer or use a compost thermometer if you have one. Measure the soil at a depth of two to three inches. The soil in my raised beds is currently just under 50°F.
If you have already purchased seedlings and the soil is too cool, then transplant the seedlings into gallon containers and keep them in a warm place until the ground warms. One friend kept them in his garage at night and dragged them out every morning until the soil warmed.
When the time comes to plant my tomatoes, I make sure the weeds are gone and the soil is smooth. Then I put cover the entire bed with clear plastic sheeting to keep the soil warm. I use pipes, boards and ground staples to keep the plastic flat. I determine how much room I need for each plant by placing my tomato cages feet up on the plastic. Then I cut a hole in the plastic inside each cage for the tomato. After I make the hole, I set the tomato cage aside but leave the plastic in place.
Tomatoes root easily along the main stem so if they are tall and lanky, dig a deep hole for them. Plant the seedling as deeply as possible, right up to the first set of leaves. Refill the planting hole with soil, lightly tamp it down, then water well.
Now place the cage around the tomato plant, pushing the legs right through the plastic and deep into the soil. Drive a stake into the ground inside the cage to stabilize it when the vine gets big. Square cages work much better than round ones. I have re-used some of my cages for many years.
As the plants start to grow, I protect them by wrapping the lower part of the cages with a couple of layers of Bubble Wrap. I secure it to the cages with clothespins. I also use a clothes pin on the plant tag so it stays with the plant. I have also used two-gallon plastic water bottles to protect small plants. I simply cut off the bottom of the bottle and place the whole thing over the plant.
Whatever method you use to water your tomatoes, be sure to water deeply. Ten minutes on a drip system is not enough. Once the plants are established, I usually water once a week. You can measure how deep the water has penetrated by pushing a piece of Rebar into the soil and noting where you meet resistance. Do not over fertilize, too much nitrogen encourages leaves not flowers. Once the flowers have begun to set fruit a dilute fertilizer or worm tea may be used every other week to keep plants healthy.
Tomatoes flowers are self-pollinating. Every morning I walk through the garden and shake the stems that have flowers on them. Bumblebees can do this for you using a technique known as buzz pollination or sonication. Their movement transfers the pollen from the anthers to the female part of the flower. Wind will also do this.
If you find a tomato you love and you want to save seeds, only harvest seeds from the healthiest vigorous and non-hybrid plants. Hybrid plant seeds will not produce the same kind of plant. Wait until the tomato ripens fully on the plant before you pick it then remove the seeds and spread them on a paper towel. Write the tomato's name and the year on the towel. Then let the towel air dry, store it in a dry place and save it until the following spring.
To start seeds, lay a piece of paper towel, seeds up, on the surface of a pot filled with soil. Water it and keep it moist. The seeds will grow through the towel to form roots. Reserve the strongest seedlings for planting.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.