Ask the Gardener: Advice on bulbs, fertilizer, and composting

Ask the Expert Gardening
Writer Carol Stocker said climate change has made some gladioli winter hardy. Adobe Stock

What to do this week: It’s time to put your garden beds to bed. Finish planting hardy bulbs like tulips with a shovel and lifting out tender bulbs like dahlias with a garden fork. There’s no need to worry about watering evergreens and new plantings, thanks to a wet autumn, so shut off water lines to the outside and clear automatic irrigation systems. Drain and store hoses off the ground. Cut down perennials in front of the house to suit neat neighbors, but leave backyard plants standing until spring to shelter hungry birds. Make your last mow of the year extra short. Rake or blow leaves off lawns, but you can leave them on flower beds and around trees and shrubs.

Q. Do I have to dig up my gladioli and dahlia bulbs to store inside? I left some in last fall’s garden, and they bloomed this year anyway.

G.R., Cambridge

A. More tropical tubers are making it through our winters than in the past, apparently due to global warming. My gladioli and voodoo lilies are now hardy here, and the occasional dahlia over-winters in the ground, too. Their survival is more likely in garden warm spots such as a south-facing slope or rocky terrace. Learn where these micro-climates are in your yard, and try some tender bulbs there.


Q. I read your response to Joe C. regarding fertilizing in late October (“Now’s the time to stop those creepy vines,’’ Oct. 21) and take issue with your suggestion of a balanced 10-10-10 fertilizer for his lawn. It was my understanding that you should not use a fertilizer containing phosphorus unless you have a soil test to determine whether you actually need it. Thanks for the “clip & dip’’ approach to controlling bittersweet. Fortunately, we do not have any in our yard, but I know many who do and will share the idea with them.

KIMBERLY R., Wilmington

A. Several sharp readers informed me that there’s a new state law to protect water quality that prohibits the use of phosphorus (the second number) except on new grass or lawns that have been tested and show a deficiency. Kimberly R. sent the following link to the law ( and also a presentation by her town’s tree warden ( in which the Massachusetts Department of Agricultural Resources is said to advise 12-0-15 fertilizer.


Q. I got a municipal Earth Machine composter from my town and need more room for leaves. When should I unload it?

R.M., Milton

A. Unload it when the compost looks like chocolate cake. Unfortunately, it doesn’t just tumble out of the hole at the bottom, like the pictures show. You have to reach in and scrape it out. Lisa Becker of the Massachusetts Audubon Society scoops out compost in the spring at Habitat Education Center and Wildlife Sanctuary in Belmont. “At home, I like to empty the bins before all the current season’s leaves get added, so I harvest in the fall,’’ Becker said. The easiest way to compost is to use only leaves, which turn into a weed-free, nutritious mulch called “leaf mold.’’ Becker collects hers with a leaf blower set in reverse, which also reduces their size and speeds up composting. Please do not bag your leaves for pickup, or you’ll remove the best organic material on your property. If you’re feeling lazy, hit the leaves with your mulching mower or just blow a big pile into a corner somewhere and wait a year to 18 months for it to break down.

Send questions and comments, along with your name/initials and community to Subscribe to our newsletter at us on Facebook and Twitter @globehomes.