Q: Some of the annuals in my containers sprout again the following year. I also have perennial plants and bulbs in some of these containers. How do I deal with these in regards to putting fresh soil in the pots? Is it necessary? Or can I simply continue to give them liquid fertilizer?
A: With shrubs, trees, perennials and anything that stays in a container for long periods, top-dressing in spring is the best practice. That is, you remove the top inch or two of soil and replace it with something rich such as compost, or potting soil mixed with a little fertilizer.
With your annual/perennial containers, you would then go on to feed liquid fertilizer through the summer in the usual way.
But container trees and shrubs usually outgrow their pot after a few years and need a totally fresh change of soil and a bigger pot. This can sometimes be postponed for a few extra years by doing extensive pruning of the top growth. But eventually a soil change is necessary.
If no bigger pot is available, root-pruning, and top-pruning are needed so that the trees and shrubs can fit into the old pot along with the fresh soil.
With annual/perennial containers it’s also best to repot in all-fresh soil every few years because perennials and even returning annuals ultimately fill all the available soil with roots. At that point, they’ll need extra space or division.
Q: Many of my big sword ferns didn’t die this winter. Should they still be cut back to let the new fronds grow?”
A: It’s still best to prune old fronds to ground level each year so that new growth has space to flourish. This is because old growth will get shabby and then you’ll likely want to freshen up the plants.
But at that point, cutting back will be a problem because new growth will have joined old growth and you’ll need to cut the old growth selectively. This is a long, painstaking process.
Q: I want to direct-seed beets and chard. Can I get going on that now? Is it warm enough? Or should I wait longer.”
A: Any time from the second week in May onward should be quite safe for planting seed of beets and chard.
Anne Marrison is happy to answer garden questions. Send them to email@example.com.