“We have a very healthy 10-year-old wisteria which grows plenty of foliage but only produces two or three blooms each year. It faces west and is growing over an arbour.
“We have tried fertilizing, extra watering, less watering, and hard pruning, all with the same result.
How can we help the plant produce more flowers?”
Theresa O’Connor, via email
Quite a few gardeners have problems getting wisteria to bloom.
I wonder if yours gets enough sun. Just because it’s facing west doesn’t mean it gets abundant sun.
Are tall trees or tall buildings in the way, turning what should be full sun into partial sun?
There’s often delay in getting a wisteria to flower, but six years is usually the longest you can expect, if your wisteria was grown from cuttings.
Seed-grown wisteria plants can wait even 10 to 12 years.
I wonder if you bought the plant yourselves, or inherited it when you bought your home.
What is under your control is fertilizer. High-nitrogen fertilizer is definitely to be avoided, because it encourages the vine to produce even more leaves, stems, and suckers than it would normally. It could be that your soil has become overly rich from the fertilization already done.
Many gardeners prune wisteria, not only hard, but also very frequently. It’s not uncommon to find them pruning long, new whippy growth and suckers once a month in mild winters. Once the pergola or arbour is covered, they keep cutting the young growth back so the wisteria continues to fit into the space it’s been given.
In late winter, the future flower buds will be the round, fat ones. The vegetative buds are thin and pointed.
I think your chances of getting more flowers are good, since you already have a few.
“My mother picked a whole lot of chestnuts off the front lawn this year in Kerrisdale, Vancouver. Are they, in fact, edible? I have been told that our variety that grows here is not.”
Danna de Groot, via email
Two different chestnut species grow here. One kind is edible, the other is poisonous.
The toxic kind (the horse chestnut) is the one that is most frequently grown here, and it’s very likely the one your mother picked.
The horse chestnut has very large leaves composed of five leaflets attached by short stems to one sturdy, main stalk. The nuts tend to be rounded, and there is usually (though not invariably) one nut in each spiny case.
Horse chestnuts are definitely unsafe. They have been known to cause nausea, diarrhea, loss of co-ordination, weakness, paralysis, and at times, even death.
The edible kind is called the sweet chestnut. It has oval leaves with serrated sides. Each leaf is on its own stalk. The top of the nut is pointed, one side often flat while the other is rounded. Frequently two or more nuts share space in one spiny capsule.
“I have a lovely pink peony in my back garden that is over-run by eight very tall Asiatic lilies. Is it too late this fall to dig the lilies up and replant them?”
It’s much safer to replant your Asiatic lilies in the spring. If a severe cold snap came along in November, your bulbs could suffer badly if they’d just been transplanted.