Yes, yes, we have now officially passed the (trumpet fanfare) “average last frost date” for our area – approximately May 15. I’ve been watching lots and lots of tomato plants leaving the big box gardening centers for the past several weeks. And Memorial Day weekend is probably the biggest week for garden centers everywhere – lots and lots more tomatoes and annuals will be heading out to home landscapes.
Now, let’s get realistic. Although it can be tempting to get tomatoes in the ground the next day after the average last frost date, that’s not the best criteria for when to plant those heat-loving plants. As a fellow Colorado gardener once said at a local landscape symposium, “A tomato never wants to go below fifty degrees in its life.” And have you noticed the night time temperatures we’ve been having? Are they consistently above fifty degrees? Not at my house! (I’ve been seeing anywhere from 35 degrees to 48 degrees since May 15.)
What happens at this point in a tomato plant’s life can have long term effects on how well it will produce for you this year. Spending energy and time recovering from colder-than-desired temperatures draws away from energy that would have been spent on getting big and setting fruit.
So….unless you have those tomatoes out under protection like a Wall O’ Water or other season extender, try to exercise some restraint in planting them at this point. Put them out for the sun and warm daytime temperatures (if the day is warm and sunny), and bring them in at night or put them in your greenhouse until we have the conditions that tomatoes really want. And if you’ve already planted them? See some tips for helping them recover once temperatures pick up in one of our earlier posts –
Contributed by Carey Harrington, Certified Colorado Gardener