Published in July, 2013 by Grit Magazine
This is my post strawberry season post. Almost. Actually because I have ever-bearing strawberry plants I will get another crop in another month or two. If these were June berries then the season would be over and it would be time do the final clean-up and put them to bed. The process is similar in both cases; it’s mostly a matter of timing.
When I planted this bed I bought plants from a nursery and set them in the spring. The Square Foot Gardening book says to plant them 4 plants per square foot, I modified that according to the number of plants in the flat (about 25). That resulted in a much wider spacing, but that’s OK.
Today I’m going in to clean up. It’s been very wet this year. Too wet. And the leaves of my strawberries are showing signs of a leaf disease which I suspect is attributed to the really wet conditions and overcrowding.
Christine Engelbrecht, of the Department of Plant Pathology at Iowa State University says: “Strawberries in this region are commonly affected by three fungal leaf diseases–leaf spot, leaf scorch, and leaf blight. These diseases typically do not cause serious damage, but when they are particularly severe, they may reduce yield and make the plants more susceptible to devastating root diseases.
Leaf spot is the most common disease on strawberry. Symptoms at first appear as small, round purple spots on the upper surface of leaves. As the spots enlarge, the centers turn pale tan to white, with a purple or rust-colored border.
Leaf scorch appears as small, irregular purple spots or blotches on the upper surface of leaves. The spots enlarge and coalesce, often covering a large portion of the leaf. As they grow, the centers of the spots turn brown.
Leaf blight begins as small, purple spots. These spots enlarge into large, triangular-shaped lesions bounded by leaf veins. The centers of the lesions turn pale brown, with dark brown margins.
Management of all three of these diseases is similar. Some varieties are resistant to leaf spot and leaf scorch. Resistant varieties include the junebearing varieties Allstar, Canoga, Cardinal, Delite, Earliglow, Honeoye, Jewell, Lester, Midway, and Redchief, and the ever bearing varieties, Tribute and Tristar. Maintaining adequate spacing between plants, and managing weeds, helps to increase aeration and reduce leaf wetness. Infected leaves should be removed after harvest to reduce inoculum levels. Fungicide sprays may also be used to prevent infection by leaf diseases.”
Based on her description, I’m thinking this is leaf scorch. Her treatment recommendation is to do pretty much what I planned to do anyway – I love it when that happens.
First I’m going in around the edges of the box where runners have bumped into the sides and rooted, producing a dense wall of young plants, and rip them out. Horrible aren’t I? I will transplant these orphans to another spot in the yard where I need a ground cover, and the birds may have the berries. Or some of them anyway.
Then I’ll snip out any diseased or dead leaves/stalks and clean out the debris around the base of the plants. Last fall’s tree leaves are still in there as well as last season’s strawberry leaves. All that needs to go. The pine straw can stay for now. Strawberries need a slightly acid soil so they LOVE pine straw.
Were these June berries, I’d perform the end of season ritual now; which I will describe in a moment. But I’m looking for another crop from these plants this year so after the clean-up I’ll take a look at the over-crowding situation inside the box.
I want to snip off ALL runners this time around. This will help the plants to direct their energies into producing berries. I will have to do this again when the blossoms appear, because strawberries are stubborn lil things about wanting to produce daughter plants via those runners. But I also want to pull out some plants where I have more than 4 plants per square foot. Leave the bigger, healthier looking plants: they’ll have the best root system, and pull out the sprouts or sickly plants. More plants does not mean more berries, or if you do get more berries they will be smaller because the plants are competing for nutrients and water in the soil. Also be sure to pull out any weeds that may have snuck in.
Speaking of nutrients, after population control it’s time for a feeding. Use a balanced, all purpose nitrogen fertilizer (10,10,10). If using a regular fertilizer try not to get the stuff on the plant’s stems, this may burn them. Side dress them – which is harder to do in a box than it would be in a row. So I use a slow release, granular fertilizer. Don’t over fertilize as this can lead to root problems and inhibit berry production.
This will have the bed ready for the late summer crop of berries. When that crop is done, the winter maintenance consists of going in with grass shears and lopping the heads off the little darlins. Cut the stems about an inch above the ground level or the top of the crown, whichever is higher. Then use a rake to pull all the debris out.
Strawberry plants will normally produce for around 3 years, so if your bed is two or more years old you will want to let the plants daughter. You can leave two runners per plant to propagate, remove the others. Apply fertilizer again and cover the bed with a couple of inches of fresh pine straw. Compost the debris you raked out.
Your strawberry maintenance chores for the year are now done and you can look forward to a bumper crop of plump, delicious berries again next year.