Ask the Gardener: Global warming tests boundaries of plant survival

Ask the Expert Gardening
Allium is an excellent bulb to plant if you want mid-spring flowers.
Allium is an excellent bulb to plant if you want mid-spring flowers. AP

What to do this week: It’s a busy and beautiful time in the garden. Plant peonies now by setting the pink buds 1½ inches below the surface. Planting too deep prevents blooming, so don’t mulch peonies either. Plant lawn grass, shrubs, trees, and perennials. If you spend your summers away, plant more colorful fall perennials at home, including aconitum, helianthus, asters, hardy chrysanthemums, and hibiscus. Water dry evergreens to help them store up moisture for winter. Squashes and pumpkins should be permitted to ripen on the vines before storing in a warm, dry place. Prune hedges for the last time.


Q. Gladioli are blooming in my garden that I didn’t store indoors last fall. Have these bulbs become perennials, or are these self-sown descendants?

D.H., Boston


A. I have them, too. I used to dig up and store gladioli and dahlias and other tropical bulbs in the basement every winter. Now I don’t bother, because so many survive the winter planted outdoors in garden beds. I call them my global warming plants. They’re small, pleasurable byproducts of a growing climate disaster. Their survival is erratic, as is our weather, so I still dig up and store a few of my favorites in the Noah’s Ark of my basement each November for spring replanting. I believe our gardens will be unrecognizable in 15 years, so don’t be afraid to experiment with more southerly species such as chaste bush, which we’re not supposed to be able to grow. My first two froze to death, but my third is 10 years old. Call it zonal denial. And what zone are we in now anyway?


Q. I am hosting a backyard wedding May 22. What bulbs should I plant now for flowers then?

SOPHI COOK, Sturbridge


A. Unfortunately, that date falls in the shoulder season after most spring bulbs such as tulips have finished blooming but before the summer ones like lilies have begun, said Becky Heath of, a family-run mail-order bulb business based in Virginia. She suggests planting the poet’s daffodil, Narcissus poeticus recurvus, which is sweetly scented and actually blooms later than tulips. Many alliums will be in bloom for the wedding, as will triteleia, dichelostemma, and eremurus, Heath said. She also mentioned one of my favorites, native camassia, a long-lived spike of blue stars. Wait until October to plant spring bulbs, but order them now. You could also sow early blooming biennials now such as columbines, forget-me-nots, wallflowers, and, of course, pansies. Tall bearded iris will also be in bloom in late May, and they can be stunning.


Purple and white bearded iris in bloom. —AP

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