Dear Anne,
“Is it time to plant tomato plants outside yet?â€
Heidi Naman, Vancouver
When temperatures are following their normal pattern, mid-May is about the right time to put tomatoes outside. Until then, nights are cold and while tomatoes may not die, they don’t grow, and take a while to recover when the weather warms.
If you have your tomatoes in pots and have a sheltered spot for them by a south or west wall, I suggest you put just one pot outside and see how the plant does.
If it grows normally and looks healthy after a few days, your others could follow. But keep watching the weather forecasts for a couple of weeks, in case an unexpected cold snap is predicted.
Dear Anne,
“My rhodos are getting dried-up leaves and buds, so I cut them off. Will this kill the rhodo? How do you care for rhododendrons?â€
Raquel, Coquitlam
Whether or not your rhododendrons die from the pruning you did may depend on how much you cut off. The rule of thumb for pruning is: never remove more than a third of your tree or shrub at one time.
It’s best to space severe pruning over several years.
Generally, most rhododendrons handle moderate pruning well – especially if they are well established and most of the branches remain with leaves that are still green.
But flowering may be reduced the year after pruning.
If the leaves you removed were brown and crispy, the plants could be badly dehydrated. That is even more likely if they were growing in pots. Ideally, rhododendrons should be grown in very large containers in mixed sun and shade, where sunshine gives gentle light and warmth and the soil is mulched to conserve moisture.
But even growing in an outside garden, rhododendrons still need watering in times of drought.
Summer last year was very hot, dry, and long, and your rhodos may not have got enough water.
If they were in pots, watering may not actually moisten them. Sometimes soil in pots can become so dry it shrinks away from the sides. When that happens, water can run down the inner sides of the pot and away.
Another issue with containers is that fierce heat in summer can attack plant roots through the sides of the pot (also an issue with cold in winter).
There are two possibilities for the dried-up buds.
Dehydration is one.
But they could also have a fungal disease called bud blast. Infected buds are brown and hard, and don’t flower. As spring continues, the bud surface develops black, furry-looking fruiting spores.
Those buds need to be removed before they continue the disease into another year.
The infection is thought to be spread by leaf-hoppers. Check the undersides of your rhodo leaves in late spring/early summer. If you see little white crawlers, they will be larval leaf-hoppers.
Insecticidal soap will kill them on contact. But like all killing sprays, it can kill beneficial insects, too – and the person applying it needs to be cautious and follow instructions.
Anne Marrison is happy to answer gardening questions. Send them to amarrison@shaw.ca