One of the great pleasures of vegetable gardening is finding new and unusual varieties to grow and tantalize our taste buds. Heirloom tomatoes are one that have surged in popularity in the past several years. Tomato enthusiasts are finding bounties of bright, rainbow colored, sugar sweet flavored tomatoes that are harvested from their gardens with pride and consumed selfishly never sharing them with friends and family. This enthusiasm is evident at your local retail garden center during spring, when many serious tomato enthusiasts mob the tables for their favorite tomato variety to satisfy their craving for these ripe sweet fruit.

In the past, our tomato season would finish at the first signs of frost and then we endure the next several months without our favorite sweet bounty.

But, what if we could prolong the season and have plants that would bring us a late harvest of fruit in what we would normally consider the off season?

Several years ago while trialling many fruit for spring time planting, we came across several varieties that actually grew well in the “off season” and produced fruit! After completion of many trials, we chose the varieties that we felt would fair well and produce in Southern California.

These are called “Cool Season” varieties not “Winter Tomatoes” as some may have suggested. They are selected for their adaptation to cooler temperatures, less daylight hours and a more humid climate. Some may call them “Siberian” varieties because of the latitudes that many of these varieties originate.

You will need to follow a slightly different set of rules when planting these varieties. It is well worth the effort to have tasteful tomatoes when the only tomatoes offered are the tasteless fruit you would normally find at the grocery store.

The rules are simple. To have a successful crop, we recommend planting these varieties starting from mid-July through the end of October. It seems strange that these off season varieties would be planted so early and in such warmer temperatures but getting your plants established in mid-summer is important. The secret is to utilize the heat of the summer to warm the soil. This in turn develops a mature root system with a larger study branching system. When the cooler temperatures arrive, the plant will be able to withstand the drop in temperature and still survive to produce fruit. In most cases if the temperatures fall into the forty degree range, these plants are better adapted to survive the cooler temperatures. If you live in an area that falls below forty, use your tomato cage from spring as a shelter and cover the cage with a breathable fabric or wrap the cage with clear plastic sandwich wrap. Leave a six inch gap at the bottom and top of the cage to allow for some air circulation and put a piece of cardboard over the top of the cage to prevent cold air from traveling down inside the cage from the open top. As long as foliage does not have direct contact with the frost, it will survive.

Most of you know that I’m an advocate for organic gardening. I found it very worthwhile using organic products.

Here is my recipe for direct ground or raised bed planting:

I use the “Lasagna Method” by layering these products over each other over the bed.

  1. Worm Castings of Malibu Compost. Add an ½ inch layer of one of these products from corner to corner.
  2. John and Bob’s Optimize. One 3 lb bag covers 1000 sq feet so a little goes a long way. I use a palm full for every plant in the bed and sprinkle it from corner to corner. This will be a very thin layer.
  3. John and Bob’s Nourish Bio Sol. This is a long lasting Organic Fertilizer that works wonders for all plants especially Tomatoes. I use 1 cup per plant and spread it corner to corner. This is also a very thin layer.
  4. The last layer is a top cover. As odd as it may sound I love to use Garden and Blooms Eden Valley Potting soil to cover the entire bed. Cover with an 1inch thick layer. You may also use your compost or mulch to cover your bed.
  5. DO NOT TILL UNDER!!! The idea for the Lasagna Method is to keep the soil intact. Tilling will disturb living microbes that have created an extensive infrastructure which has been developed to deliver nutrients to your plants root system.

For container planting:

Select a pot size large enough for a small tomato plant. Usually a 3 gallon to 5 gallon pot is large enough since cool season tomato plants have smaller root systems. If you still have your 15 gallon sized pot from the spring, use it! You can plant 3 plants into a 15 gallon sized container.

  1. Soil preparation is almost the same as planting in the ground or in raised beds.
  2. Fill your container with your potting soil ¾ full. I use Garden and Blooms Eden Valley Potting soil. Add a ½ inch layer of worm casting or Malibu Compost. Add a 4 oz layer of John and Bob’s Optimize. Add a 1 cup layer of Nourish Bio Sol. Fill the container to the top with Eden Valley Potting soil.
  3. You are now ready to plant your plant. No mixing necessary. Use water percolation and gravity to mix the products for you!

Seaweed extract or Bu Best compost tea is used as a foliar spray to increase plants resistance to cooler temperatures..

An overlooked product that helps increase the plants ability to thrive is adding Humic Acid or decomposed humus. (Layer number – John and Bob’s Optimize)
In an experiment we conducted several years ago, found that using fertilizers with Humic Acid help prevent our test plant from frost damage. Humic Acid stimulated the plants ability to create a larger canopy of foliage which translates into the amount of sugars it would produce. These sugars in their vascular systems act like anti-freeze as they do in your automobile’s engine and protects the stems and foliage from frost damage. Our trials have proven unprotected cold temperature survivability down to 36 degrees.

Synthetic fertilizers have proven to be sure death to cool season tomatoes as the forced growth causes inferior cell development that cannot with stand temperatures below 40.

Suckering or removing side branches???

A little tweak to spring/summer tomato growing is that I do not recommend pruning or removing of side branches. I found that during the cooler nights an extra layer of foliage acts as a protective cape to keep the inner core of the plant warmer and aiding in flower pollination.

Water as necessary. Tomato plants still need as much water in the cooler season as they need in the summer. The only constant that changes is the humidity level and the rate of evaporation. I prefer a deep watering every 5 to 7 days in pots and 7 to 10 days in your garden beds. Remember that rain counts as a watering. (Rain? Whatever that is?)

Staking is not a real issue here. Most to the plants are determinates and only grow to 3 feet tall. A short tomato cage is enough just to support the plant.

This year Rogers Gardens will be carrying 10 cool season tomato varieties specially selected by Steve Goto for their ability to perform in our local coastal climate. They are available now through the end on October.