June is for perennials. It’s a promotional slogan for the plant industry, but it also makes sense: Now you can see your own perennials have emerged and you still have time to divide, thin and move them around.
Now you can find most perennials out on the tables in garden centers, and many are flowering. And now our gardens have dried out – mostly – and we can finish prepping the beds and planting our flowers.
Make a fresh bed
Starting a new perennial bed or renovating an old one calls for several steps. Beginners sometimes skip the prep, and begin with buying and planting in the old soil – but if you do the hard work first you will be rewarded with less work and a better garden later.
1. Choose and understand the site. You must understand the site: how much sunlight or shade, the soil type and quality, wind, drainage and likely animal intrusions. If you have garden failures there, get a soil test from Cornell Cooperative Extension to see if the pH or certain nutrients need adjusting.
2. Decide on raised or ground-level beds. Most perennial roots need at least 18 inches of good, penetrable soil. For new raised beds, remove weeds and sod, and loosen up the base soil before building on top. Remove weeds and sod from flat garden areas also.
3. Improve and prepare the soil. For raised beds, add high-quality commercial garden soil or compost-rich topsoil. For in-ground beds – often heavy clay – spread several inches of compost and/or top quality garden soil. Turn the amendments lightly into the old clay, leaving it lumpy. Don’t pulverize it.
4. Then buy plants and place them properly!
Once the soil is ready, do this:
• Dig a hole as deep as the plant’s pot, and at least twice as wide. (Plants settle too deeply into a very deep hole.)
• Remove the plant from the pot, keeping the root ball together.
• Stretch the roots outward only if they look pot-bound and circling.
• Place the plant so its crown or top is a tiny bit above ground level.
• Fill the hole half full with water and let the soil settle.
• Backfill around the plant with the compost-rich soil.
• Pat it down – don’t stamp with your feet – and water again.
• In coming weeks, check soil often. When it’s dry an inch down, water until you have saturated it to the depth of the root ball.
Even “drought-tolerant” plants need time to grow roots. Drying out is a killer.
I have favorites – some for shade, some for sun, some for in-between. Some spread, and some stay tidy. Some flower early, some late, and some repeat flowering. Some have many species and cultivars. Shop for these in your favorite garden centers. I apologize for those left out. (There are listed as commonly named in our region, grouped by flowering period):
Early season: Bergenia (Pigsqueek), Brunnera, Campanulas (Bellflowers), Dicentra (Bleeding Heart), Digitalis (Foxglove), Epimediums, Hellebores, Rodgersia, Solomon’s Seal.
Midsummer: Astilbes, Daylilies, Echinacea (Purple Coneflower), Filipendulas (Meadowsweet), Monarda (Bee Balm), Penstemon, Thalictrum (Meadow Rue), Rudbeckias, Veronicastrum (Culver’s Root), Vernonia (New York Ironweed), and many daisies, salvias, veronicas.
Later season: Aconitum (Monkshood), Anemone x hybrida (Japanese Anemone), Helianthus, Helenium, and Sedums.
All-season interest: Stachys (Lamb’s-Ears), Heuchera (Coral Bells), and – always, above all others – Hostas.
Exceptional or new
Sometimes one must bow to the work of hybridizers, as in the following plants – just examples of exciting new beauties in perennial departments and at shows:
• Astilbes ‘Delft Lace’ and ‘Deutschland’
• Baptisia ‘Lemon Meringue’
• Echinacea ‘Kismet’ series
• Hibiscus ‘Holy Grail’
• Perovskia ‘Denim ’n Lace’
And so many more. Go forth and garden with perennials.
Finally: Shopping tips
Remember September: Perennials that bloom later in summer don’t look impressive yet. They’re just green shoots in their pots. Look for them, read the labels, and plant now for a late-season show.
Don’t believe your eyes: Plants may be 1 or 2 feet tall now, but some will grow to 5 feet or more, even in one season. Read the expected mature height, width, and spreading habit on the labels and give them room. (This applies to annual plants, shrubs, and trees as well.)
Sally Cunningham is a garden writer, lecturer and consultant. She and Jim Charlier are the authors of "Buffalo-Style Gardens: Create a Quirky, One-of-a-Kind Private Garden with Eye-Catching Designs" (St. Lynn’s Press, $24.95).