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In the Garden: Fertilizers not the only blueberry pitfall

Dear Anne,

“Last year I had few berries on my plants. What is the best fertilizer for blueberries?”

Neil, South Langley

Poor blueberry crops may not be caused by lack of fertilizer. In order to produce well, blueberries also need acidic soil, lots of water in dry spells, at least one other compatible blueberry nearby, and (in some areas) protection from birds.

But if you’re sure your blueberries need fertilizer, liquid fish fertilizer is good, because it acidifies the soil.

Fertilizer for acid-loving plants such as rhododendrons or azaleas is also excellent for blueberries.

Blueberries given too much fertilizer develop lush growth that can die back in winter. High nitrogen fertilizer is especially damaging, and does nothing for berry production.

Wood shavings or sawdust can help acidify the soil when you plant blueberries, and also makes a good mulch for them.

Peat moss is a great acidifier if you dig it in when you plant blueberries, but it’s a terrible mulch, because once it gets dry water runs off instead of soaking in.

Blueberries may have short of water last summer. It was hard to keep up with watering, as last year’s drought went on so long.

The number of blueberry plants can also have an impact. Blueberries self-pollinate, but produce bigger harvests if there are three bushes of compatible kinds – but one of them must be of a different species.

Compatibility depends on the blueberries flowering at the same time, so that pollen can mingle. Nurseries normally sell compatible kinds together.

Birds steal the berries. Some gardeners don’t get any berries unless they net them. And in rural areas, bears may harvest blueberries.

Dear Anne,

“Is it possible to prune a Japanese maple tree without sacrificing its beautiful pendulum shape? I have a two-foot treeling (as I call small trees) on my balcony, and I would like to keep it small enough to move. With bursitis in my shoulder, my new motto is, ‘If I can’t lift it, I can’t have it.’”

Caroline Moore, New Westminster

Japanese maples need very little top-growth pruning, just the removal of diseased, broken, or dead branches.

In order to keep it small and weeping, it’s far more use to keep the roots pruned. It doesn’t need to be done every year – usually every three or four years is about right.

Pruning the top growth will only encourage the tree to grow faster, but pruning the roots reduces the vigor available for the tree’s growth process, making it easier to retain the lovely drooping shape, and you should be able to keep it in the same pot for many years.

Actually, what you will be trying to achieve is something similar to a bonsai tree, though less intricate and on a different scale.

Dear Anne,

“I have a single pear tree, planted four years ago. When is the best time to graft it?”

Ann Parker, Terrace

Early spring when the buds on your tree begin to swell is the best time to graft it.

The swelling of the buds show that sap is beginning to move, and it will be ready to surge from the tree into the graft.