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In the Garden: Fall time to prune

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Anne Marrison

Because of our changing weather, fall is now the safest time to plant trees and shrubs or move them. They all need several months of moisture to settle in and so far our winters provide that.

Grass is continuing to grow and people with vegetable gardens can use grass clippings as a nitrogen-rich weed-blocker. Grass clippings are also a great nursery for earthworms.

Fall rye is another useful cover for winter veggie beds. Fall rye’s myriad fine roots leaves the soil soft and workable once the top growth has been cut and composted. Just don’t let it go to seed.

Leaves make yet another good mulch, though they tend to blow around until they’re thoroughly moistened or rained-on. They add valuable carbon when they’re layered-into compost.

Some gardeners bag their leaves and gradually add them to compost through the winter. An easier alternative to bags is hoops of small-mesh wire netting. A twist-tie top and bottom is usually enough to complete the encirclement.

Leaves also make a good mulch for shrubs and perennial flower beds. If some perennial stems and seed-heads have been left for birds to forage on, these form a loose barrier to stop leaves from taking flight again.

Once leaves have fallen and you can clearly see the shape of deciduous trees and shrubs, it’s a good time to prune. In fact some trees should be pruned in late fall or early winter because they’re ‘bleeeders’ and can drip sap for weeks if they’re pruned in spring when sap is on the move anyway.

These ‘bleeder’ trees include birches, maples, laburnums, magnolias, honey locust, lirodendron and willow. Interestingly enough, with sugar maples and birches, the bleeding tendency has been exploited so that today we have maple syrup and birch syrup.

Climbing roses are also best pruned now, cutting back smaller side branches a few buds away from the main frame. Most other rose bushes are best left until late January or early February when the buds begin to swell and redden.

It should be time to take in plants which have been left outside all summer. These include Christmas cactus and all kinds of houseplants. Every one needs to be checked over for unwelcome visitors.

This can include serious problems such as mealy bugs and whiteflies to more benign nuisances like spiders and sowbugs. All can cause problems for other houseplants. Sometimes summering houseplants placed on soil for summer can root down through the drainage holes. If these are big, important roots (this can happen with shrubby houseplants), the plant will suffer from having them severed. Then you’ll need to prune some top growth to keep your plant in balance.

Bulbs and tubers of tender plants need to be taken into inside storage.

These can include dahlias, gladiolus, canna lilies and calla lilies.

Predictions are for a warm winter, but leaving them outside may mean checking the weather forecast every day then needing to bring them in.

The white calla aetheopica can be left outside if it’s in a warm garden setting and deeply mulched. So can pleiones and some tender fuchsias. It’s a gamble that some gardeners take.