January 20, 2023: Dormant pruning; germination tests; new garden beds

From Linda Gilkeson:

With days noticeably longer and our last month of serious winter coming up, gardeners are itching to be doing something. It is too early to think about garden cleanup or starting seedlings, but it is a good time to start pruning fruit trees, plan the vegetable garden and get seeds.

Dormant pruning: On a dry day (there are some in this week’s weather forecast!) you might want to start pruning fruit trees, grapes, kiwi and berry bushes. If you don’t have many plants to do, you can wait until February, but if you want to get out in the garden or have a lot to do, go ahead and make a start now. Aim to have all dormant pruning done by the end of February. I just finished pruning my super dwarf apple trees (on M27 rootstock) and was struck, once again, by how much I appreciate these small, productive trees. It only takes about 10 minutes to prune each one, no ladder needed, yet they carry large crops of full-size fruit.

With the warm weather last October, which caused trees to keep on growing, some fruit trees didn’t drop all of their leaves before winter. This is a concern for apples because the apple scab fungus overwinters on intact apple leaves—and last year was the worst year I have ever seen for apple scab infections. Raking up and composting fallen apple leaves to make sure they have all disintegrated by spring destroys the overwintering spores. If trees still have some leaves hanging onto the branches, however, these can provide spores to start up an early infection cycle on new leaves. So while pruning, be sure to strip off all remaining leaves and also remove dead flower clusters and tiny mummified fruit that might still be clinging to twigs. If it is impractical to rake up fallen leaves and compost them, spread a clean mulch on top of the apple leaves, such as straw or leaves from unrelated trees (e.g., maple or oak). This speeds decomposition of the apple leaves and helps to prevent surviving spores from being bounced up to lower leaves by spring rains.

If it is unrealistic to remove every remaining leaf on very large apple trees, it might be a good idea to apply a lime sulphur dormant spray to control the scab fungus on the leaves. I never advocate routine dormant oil or lime sulphur sprays because they are only useful for some pests and diseases. If those problems are not present, not only will the sprays do no good, but they will needlessly kill beneficial mites and other non-target creatures overwintering in crevices of bark. Lime sulphur sprays applied to bare branches don’t normally control apple scab because the fungus is on leaves on the ground, but if leaves are still on the tree, then a dormant spray should help to clean up overwintering scab spores on leaves.

Depending on where you are, you might also need to remove tent caterpillar egg masses from fruit tree branches while pruning. I been finding an awful lot of egg masses, so this will be a big year again for tent caterpillars on Salt Spring. To see what egg masses look like in dry weather: Linda Gilkeson | West Coast Gardening | West Coast Gardening: Natural Insect, Weed and Disease Control . In wet weather, egg masses look darker and rougher than in this photo and are hard to see. Look for them on small branches the diameter of a little finger or a bit smaller, but not on trunks or thin branches and twigs. Note that dormant oil sprays won’t help to control tent caterpillars: those egg masses are well protected from pesticides.

If you don’t know how to prune your fruit trees, get some help as fruit trees do need to be regularly (and correctly) pruned. If you hire someone to prune trees this year, watch what they do so you learn what to do next year. Sometimes pruning workshops are organized by local garden clubs or are held with Seedy Saturday events and there are also videos on YouTube. If you know someone that is expert at pruning their own trees, ask if you can watch them this year. Figs are a type of fruit tree that is often pruned incorrectly so be sure that you (or anyone you hire to prune figs) are pruning correctly for figs in a cool climate. Figs in warm climates are pruned entirely differently so don’t follow info from a California website, for example. To prune figs in this region, have a look at the video Bob Duncan has posted on his Fruit Trees and More web site: https://www.fruittreesandmore.com/

Germination tests: If you are wondering whether seeds you have from previous years are still good, you can do a quick germination test. Just fold a few of the seeds into a moist paper towel, put it into a plastic bag or covered container and hold it in a warm place for a couple of days. Most seeds germinate enough to see the tiny white root tips poking out in 2-4 days. Ideally, you should test 10-20 seeds, but if you don’t have many left, just test a couple. If 75% of the seeds germinate, that’s fine, but if less than half of the seeds germinate, sow lots of extra seeds to make up for the lower germination and plan on getting fresh seeds (or saving more) for next year. If you take good care of seeds by keeping them very dry, they remain viable for years longer than you might expect. I just checked some kale seeds I saved in 2011 and over 95% germinated! To keep seeds dry an excellent investment is a dehumidifier pack that fits inside a jar or box of seeds. Lee Valley Tools sells small metal boxes filled with silica gel crystals; they can be heated in an oven to renew the crystals and last for decades (I have had one since 1990). These are used in toolboxes to keep fine woodworking tools dry so don’t show up in the gardening catalogue (look for them under ‘dehumidifiers’). The small 40 g box is enough for a large box of seeds; they also sell bags of silica gel to dehumidify larger spaces.

Seed discount: After mentioning the BC Eco-Seed Co-op https://www.bcecoseedcoop.com/ as a seed source in my previous email, they set up discount codes for readers of my mailing list. To receive a 15% discount on your seed order from now until April 30, use this code: “Linda15”. From May 1 to August 31, 2023 use “Linda30” to receive a 30% discount.

Making a new garden? I should have mentioned this last fall, but a couple of recent questions from new gardeners reminded me to add this. If you plan to have a garden where there is currently lawn or soddy/weedy vegetation, the easiest way to convert it into a garden is to cover the area with opaque material (heavy tarps, cardboard) for 3-6 months. Hold down the edges with boards or rocks so no light gets in from the edges. If you do that right now (this weekend!), the first beds could be planted at the end of April. The benefit of doing this is that you keep the best topsoil you have, which is in the roots of the sod, in the garden. You also retain all that lovely organic matter from the killed roots and tops of the grass and weeds. Once the vegetation is killed by excluding light, all you have to do is lift the cover, spread compost and other return the soil to the garden sometime later. It takes longer to kill creeping buttercup and morning glory so if these are infesting the soil, covers need to be on for full 5-6 months. The covered area should also be several feet larger in all directions than the intended garden beds. These plants have runners that can continue to feed plants under the edges of the covered area so it take longer to smother them.

Upcoming event: Sunday Feb 12, 2023 2:30 pm. Resilient Gardens for a Changing Climate.

This presentation is open to everyone via Zoom. It is a fundraiser by donation to Transition Salt Spring, an organization working to address climate change at our community level that I want to support in every way possible. If you have seen an earlier version of this talk, I invite you to join us again, as I continually update the information.

Summary: Our regional climate is transforming rapidly as the global climate changes, with extreme weather events setting records. What does this mean for our food gardens and landscapes? How can we take on the challenge of increasing local food resilience and enhancing our landscapes ecologically to respond to our changing climate? Learn how extreme weather affects plants, including trees, and how to design resilient food and ornamental gardens that help plants survive our changing weather patterns. Discover the important role gardeners can play in mitigating greenhouse gas emissions, including designing landscapes to capture carbon. To register: Resilient Gardens for a Changing Climate – Transition Salt Spring Society

Republished with permission from Linda Gilkeson’s Gardening Tips. See Linda’s website to sign up for her newsletter, purchase books, access free presentations and identify pests and diseases which may affect West Coast gardens.