One of the best moments of a Minnesota summer is the day I pick my first homegrown tomato.
The way I look at it, anyone who has to live through arctic winters deserves to rejoice when once-frozen ground yields juicy, sweet fruit that puts the rock-hard tomatoes we get in winter to shame.
Growing tomatoes is easy, but you’ll get bigger, better and more tomatoes if you know how to make the plants happy. It’s not hard.
Just follow this advice:
Give them room
Tomatoes need full sun, regular watering and plenty of space for their roots. The only tomatoes that do well in pots are the so-called patio varieties. Everything else needs to go in the ground or in a raised bed.
You have two main choices among plants: hybrids or heirlooms.
While heirlooms are all the rage, they are not as easy to grow as are hybrids. Most heirlooms have no resistance to the diseases that spot tomato leaves and turn entire branches brown and crisp. In contrast, hybrids have been bred to resist disease.
How can you tell them apart? Just look at the plant label. Celebrity, a hybrid with baseball-sized fruit, will have the initials “VFNT” under the name on the tag. That means the plants are resistant or tolerant to verticillium and fusarium wilt, nematodes and tobacco mosaic virus.
Widely available tomatoes like Beefmaster, Better Boy, Champion and Early Girl will have anywhere from one to four initials on their labels, indicating some disease resistance. Heirlooms like Brandywine and Mortgage Lifter won’t have any initials.
That doesn’t mean you shouldn’t plant heirlooms. But to keep them healthy, you’ll need to pay attention to where you plant and how you water them.
Tomato diseases come from fungi that live in the soil and remain active there for many years. The best way to avoid those diseases is to plant your tomatoes in a different location each year. If you can’t do that, planting disease-resistant varieties will reduce your problems.
Watering is also key. Giving the plants a deep drink every few days in hot weather will prevent the fruit from cracking and help prevent blossom-end rot, where black or moldy spots appear at the bottom of fruit. Avoid watering with a sprinkler. Instead, hold a hose at the base of the plant to keep the leaves dry, reducing the possibility of disease.
Mulching under the plants also cuts the chance of disease by limiting water (and perhaps fungi) from splashing on the leaves. It preserves moisture and saves water, too.
Good air circulation also wards off disease, so give your tomatoes plenty of room when you plant them. (Keep in mind that your little seedlings will probably grow to 2 to 3 feet wide when they’re bearing.)
It’s also wise to plant tomatoes deep. Snip off the bottom set of leaves, so you can bury the stem deeper. Roots will sprout where you removed the leaves, giving your tomato a stronger root system.
For protection against cutworms, wrap a little newspaper around the stem when you plant, making sure it protects the stem an inch below the soil and an inch above. The paper will deteriorate, but by the time it falls apart the stems of your plants will be too thick to be damaged.
Offer warmth, support
Tomatoes don’t grow until the soil is warm, so don’t let your eagerness overtake good sense. Tomatoes that are planted when the ground is still cold will sit and sulk and may even rot if it’s wet. Planting in the latter half of May — and keeping an eye on the extended forecast — is the safest bet.
And don’t forget to stake your plants. Tomatoes can be heavy and branches will break if you’re growing a variety like Brandywine that has big fruit. Letting branches and fruit lie on the ground only creates disease.
Slice and enjoy
Because I have limited sun in my back yard, for the past five summers I’ve planted one heirloom tomato, a disease-resistant cherry tomato and several Celebrities in two raised beds. Though I had good success with the heirlooms at the start, last year I found that even rotating the heirloom between the two beds, replacing some of the soil and careful watering did not stop disease. In contrast, the Celebrities were perfectly fine and bore a lot of fruit right into September.
So this year, I’m skipping the heirloom tomatoes. But it won’t diminish my enjoyment of plucking that first Celebrity off the vine, slicing it up and eating it before the warmth of the sunshine is gone from that wonderful red flesh.
That’s a true summer treat.
Mary Jane Smetanka is a master gardener and Minneapolis-based freelance writer.