Marianne C. Ophardt
WSU Extension Faculty
for the Tri-City Herald, Kennewick, WA
Longtime gardeners have learned their tips and tricks by trial and error and from other gardeners. Earlier in the year I gave novice gardeners a few tips on growing great veggies. Now, here’s some helpful tips on growing great tomatoes.
Stake or Cage Tomatoes? Tomatoes are the favorite crop of home gardeners. What varieties did you pick from the staggering number of choices available at garden stores? Do the ones you planted have determinant of indeterminant growth habits?
Determinant tomatoes are more compact with growth that’s easier to contain. They grow to a predictable height and then flower and set their fruit over a relatively short period of time. The smaller "bush" types that grow three feet tall or less usually don’t need any extra support in the garden. However, the taller determinant varieties may benefit from the support of wire cages, especially with the "occasional" windy days encountered here.
As "vines," indeterminant tomatoes keep growing and growing until frost kills them in the fall. They flower and set fruit over an extended period. You can allow the vines to sprawl along the ground, but this makes them difficult to tend and takes up valuable garden space. Caged or staked upright, indeterminant tomatoes will take up less space. I favor wire cages because they require less work.
You can make your own cage out of concrete reinforcing wire or purchase a sturdy one from the garden store. For determinant tomatoes you should have a cage that’s at least 4 to 5 feet tall and 2 feet wide. As the tomatoes grow, you simply redirect stems that escape the cage, placing them back inside. If you anticipate heavy vines or have a windy garden spot, it’s a good idea to secure the cage to a couple of stakes hammered into the ground.
Even Soil Moisture is a Key to Tomato Success
One key to success with tomatoes is maintaining even soil moisture. This is best achieved by checking the soil moisture regularly and watering when needed. A thin layer of mulch, such as grass clippings or compost , will help conserve soil moisture and moderate soil temperatures. Close attention to soil moisture will help avoid blossom end rot and fruit cracking, both common abiotic disorders of tomatoes related to soil moisture.
When Tomatoes Don’t Produce Any Fruit
Tomatoes are self-fertile and depend primarily on the vibration of wind for pollination to occur, but they’re notoriously finicky about day and night temperatures, as well as humidity, watering, and fertility. Most tomatoes set best when temperatures are between 70 and 90 degrees and will drop their blossoms without setting fruit if:
1. Night temperatures are too low - below 55 degrees F for four or more nights
2. Night temperatures that are too high - above 75 degrees F
3. Daytime temperatures are too high - above 90 degrees F
4. Water stress and excess soil moisture
5. To much nitrogen in the soil or too little
6. Low humidity, below 40 per cent. You may be able improve blossom set when the weather is hot (between 90 to 100 degrees) and dry (below 40 per cent humidity) by spraying the blossoms with water twice during the hottest part of the day.
Find out from other gardeners in your area what tomato varieties produce the best for them. They can also tell you their "tips and tricks" for growing great tomatoes