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Mouldy berries a clue to general wetness issue

Raspberry roots rot if drainage is poor

Q: My raspberry bushes used to be heavy producers, but last year after having good green growth and lots of flowers, they gradually deteriorated. First the leaves turned yellow then brown, and most of the small berries stopped growing and either shrivelled up or became mouldy. This spring, the same problems have been repeated. Do you have any suggestions as to the problem and solution?

Ian Clague, Vancouver

A: We've had two very wet springs in a row-and though raspberries like moisture, their roots rot if drainage is poor. I wonder if you garden on clay soil? Clay waterlogs easily. Mouldy fruit is a definite clue that your canes are having a problem with general wetness.

The frequent grey skies this year wouldn't have allowed the plants and soil to adequately dry even when the rain stopped. Though root rot is caused by excessive moisture, symptoms usually resemble drought since there are too few healthy roots left to transfer moisture up the stems to the leaves.

Another possibility is that your raspberries also have a viral disease. This often happens with older plants. Raspberries are prone to virus attack.

Could you buy new plants and make a raised bed for them in another part of your garden? This should have compost added to it- ideally a compost-and-sand mix. If you haven't enough of your own compost, you could add some commercial compost. It's possible to get commercial compost with a percentage of sand added.

Once the plants are in place, mulching conserves moisture without being overly moist and also deters weeds. Grass clippings are useful, but fine bark mulch is also good. Raspberries like somewhat acidic soil.

One variety that might interest you if you like a longseason crop is the late-summer raspberry Tulameen. It produces from late sum-mer till frost and is easy to look after since it can just be sheared to the ground in autumn.

This benefits winter and early spring crops in a small garden by ensuring they don't get shaded by raspberry canes.

Q: I have a couple of roses in my garden that were planted by the former owner. I want to plant another rose. When is the best time of year to plant?

Ramzan Patni, Richmond

A: It's not too late to plant a rose sold in a container. But it must be kept well-watered if we get a dry spell.

Summer is not a good time for a bare-root rose to be dug and moved, but potted roses transfer into the ground easily because all the roots stay intact.

Q: I deadheaded my peonies and they have very green leaves. Do I let them and the leaves of my columbines stand until winter? How far down do I cut delphinium flowers so that they bloom a second time?

Heidi Hilmar

A: The peony and columbine leaves should be left through the growing season. In late fall, the peony leaves should be removed. Growing plants need their leaves to carry on photosynthesis, which provides nutrition and strengthens the plants so that they flower next year.

Flowered stalks of delphiniums should be cut back to a leaf or a stronglooking bud.

Anne Marrison is happy to answer garden questions. Send them to amarrison@ shaw.ca.