Q: I want to add spring bulbs to my garden but have limited space given how many mature perennials and shrubs are already growing there. Can I squeeze them in somewhere else?
A: Autumn is bulb-planting season for all of those spring-flowering jewels like tulip, daffodil, crocus, aconite, hyacinth, and snowdrops, and fortunately they don’t take up nearly as much space as your typical perennial in terms of the planting site. I would not dig into the root system of an established perennial or shrub – too risky for causing damage that might result in dieback or reduced overwintering success – but you can certainly fit them into spaces between. You probably don’t want too many under the canopy of a shrub. Depending on how early it leafs out, the shrub could block needed sun and rainwater from reaching the bulbs below, but around its perimeter should be fine.
Good companions for early-flowering bulbs are late-sprouting perennials, so that by the time the bulbs are looking ragged and losing foliage for summer dormancy, the perennial is hiding it with fresh foliage.
One creative option is to scatter some of the minor bulbs in your lawn, if you won’t be walking on that area too often and compacting soil or crushing foliage, and if you don’t need to start mowing soon after blooms begin. Candidates include Crocus, Glory-of-the-Snow (Chionodoxa), Siberian Squill (Scilla siberica), Winter Aconite (Eranthis), Reticulated Iris (Iris reticulata), and Snowdrops (Galanthus). Be advised, though, that a few of these species might be prone to naturalizing outside of your lawn, so use caution around woodlands and parks.
Native alternatives with bulb-like underground structures include Spring Beauty (Claytonia), Squirrel-corn (Dicentra canadensis), and Dutchman’s-Breeches (Dicentra cucullaria), though the Claytonia is the only one that may stay short enough to be mown-over high and whose foliage blends-in well with the grass. Many of our native ephemeral wildflowers – early-season bloomers that go fully dormant come summer – are unfortunately harder to find for purchase.
Growing bulbs in containers would be your other option, but this can impact winter hardiness since the bulb’s root system is fully above-ground, not benefitting from the insulation of being planted in the earth. Potting mix also dries out faster than in-ground soil, so it might be challenging to make sure dormant bulbs in pots don’t get too dry while also not accidentally over-watering them. If the container is large enough, you can layer two or three tiers of bulbs at different depths so they bloom in succession, or use bulbs planted below annuals or shallow-rooted perennials to provide summer color. Bulbs are planted at different depths depending on the species, though, so take note of planting instructions when you select which to purchase and decide where to plant.
By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.
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