What to do in the garden this weekend: Feed your plants with wood stove ash

This is a good time to buy and plant trees, shrubs, and perennials. Get more advice from Ask the Gardener’s Carol Stocker at realestate.boston.com.

Now is the time to pull invasive garlic mustard. Debee Tlumacki/File 2017

May 2, 2019

3 minutes to read

What to do this week: This is a good time to buy and plant trees, shrubs, and perennials. Direct sow seeds of carrot, dill, broccoli, spinach, pea, radish, and beet outdoors, as well as bachelor’s button, sweet pea, and larkspur, but wait a few weeks to buy young annuals. But you can plant seedlings of frost-resistant vegetables such as cabbage, Swiss chard, kale, lettuce, and collard greens now. Plant them outdoors on an overcast day at the same depth they are growing in their trays (not deeper). Placing a floating row cover over these crops will help protect them from insects and chilly nights. Start seeds of melon, cucumber, tomato, and basil indoors under grow lights. Snap off spent flowerheads on hyacinths and daffodils, but spare stems and leaves until they “ripen’’ (turn yellow) in early June to store energy for next year’s performance. Remove old tulip bulbs and leaves that did not produce flowers this year. They never will again. Tulips are swoony gorgeous but expensive annuals. Plant or move hardy herbs outdoors. Surround sprouting peony stems with grow-through hoops now to keep heavy flower heads standing tall next month. Pull weeds while they are blooming so you can recognize them but before they go to seed. Target garlic mustard, which has ragged, pointed leaves and small white flowers with four petals. It’s easier to pull out than most invasives, but will produce thousands of babies if you don’t get around to it. An asparagus fork will pry out tougher weeds with long taproots such as dandelions. Spray poison ivy with an herbicide now while the leaves are tiny and red. When they turn green, they are protected by a waxy coating. Finish cutting last year’s straw-like tops off perennials, and pull back mulch to make room for fresh new sprouts.

Q. We burn hardwood in our wood stove, which produces a catch pan full of ash. Is this something that would be beneficial to add to the soil for ornamentals or edibles? Would it be better used as a mix-in for compost?

T.B.H., Northampton

A. Wood ash provides potassium and trace elements for plants. Have you noticed how green the grass sprouts in a field after it has burned? Wood ash also raises pH, which is beneficial for lime-loving plants such as grass, lilacs, and roses. You can scatter it thinly around the garden. Just avoid acid-loving native plants like dogwood trees and blueberry bushes. (Most of our native plants have evolved with acid soil because that’s what we’ve mostly got here.) You can also compost ashes.

Q. Which wildflowers are suitable for Eastern Massachusetts? A listing of nurseries where one can get reliable advice on native plants would be helpful, too.

D.B., Bedford

A. For shade, my favorites include sculptural Jack-in-the-pulpit (Arisaema triphyllum) and hummingbird attracting Solomon’s seal (Polygonatum), which has flower buds and stems that taste like asparagus. For sun, I like any kind of milkweed (bright orange Asclepias tuberosa is the most colorful) because they host black and orange monarch butterflies. Visit Garden in the Woods, the Native Plant Trust’s headquarters (80 Hemenway Road in Framingham), for the largest landscaped collection of wildflowers in New England — a thousand-plus species. Many are in bloom right now. Admission is $14, but supports conservation, education, and more. You don’t need to pay to visit the attached nursery of natives the society propagated, including many hard to find elsewhere. The group, formerly known as the New England Wild Flower Society, also owns Nasami Farm (128 North St. in Whately), which sells plants on weekends. The group will host guided trillium tours May 5-11. Visit NativePlantTrust.org or call 508-877-7630 for more information.

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