Beat the Blight, How to Avoid Late Blight on Your Tomatoes

If you’ve had a beautiful looking crop of tomatoes ruined mid-season by a nasty case of late blight, you’re not alone. It’s a major problem that has been rearing its ugly head in gardens in the province. While late blight is a challenge to deal with, a beautiful, delicious, homegrown tomato is still possible with a bit of knowledge and the right varieties.

What is late blight?

Late blight is a disease that thrives in cool, cloudy, wet conditions and affects tomatoes and potatoes. Some resistant varieties of tomato are now available; more on that in a bit. Late blight can set in quickly, the spores blowing from nearby affected plants, and kill a healthy plant in a matter of days. Affected plants can develop large olive-green to brown spots on the leaves, brown-black stems and firm brown spots on the fruit.

How do I treat late blight?

Treating for late blight is difficult and often undesired for many gardeners so watching for the signs and removing affected plants immediately (off site) is important to prevent the spread. Many tomato fans have come to us looking for help and we’re happy to report varieties are finally available that are resistant to the blight.

While there are no varieties that are completely immune to late blight, breeders have been working hard to develop new varieties that are resistant to the fungus.

At Heeman’s, we have selected four new varieties to offer for your consideration this spring if blight is a real concern for you.

• If you’ve always been a fan of a delicious cherry tomato, Jasper is an All-American Selection (AAS) winner with a sweet and rich flavour packed into small, round 7-10 gram tomatoes. As an added benefit it’s a vigorous grower and also resistant to cracking and rot.

• Canning and saucing tomatoes can be a great way to store a bumper crop away for cold winter days. In place of the traditional Roma tomato, try Plum Regal as a blight resistant plum-type tomato that is ideal of saucing. It has a deep red colour and high yields of 4 oz. tomatoes.

• For those fans of a great BLT, we have selected Defiant, a variety that was bred with flavour in mind. This variety is highly resistant to blight and offers high yields of 6-8 oz. glob-shaped fruit perfect for slicing and serving on a sandwich. If you’ve had issues with your Bonnie Best, this is a nice alternative for your garden.

• When it comes to large tomatoes, few are better known than the classic Beefsteak variety. This long time favourite is not without a few notable faults; the eventual cracking and major susceptibility to blight. Enter Mountain Merit, a medium-large blight resistant variety that is a bit smaller than Beefsteak with 8-10 oz fruit, but offers resistance to late blight, nematodes, tomato spotted wilt virus and fusarium wilt. While not quite as flavourful as Defiant, it was selected as an AAS winner and worth your consideration.

You can find these varieties of tomatoes, along with over two-dozen classic favourites and heirloom varieties in all colours and sizes in the veggie section at Heeman’s. For more help with selecting varieties or planning your edible garden, check the other guides on our site or come in and visit with one of our Daymakers!