What about later in the season? Have your perennials do double duty come late summer and fall. When perennials fade, gardens can begin to look worn at the height of summer heat.
If you want a repeat performance, get out those shears and fertilizer. When midsummer rolls around, it is time to deadhead and cut back plants that bloomed in June. For plants that disappear, just make sure to have the replacement plant up to bat next – especially those summer bulbs.
Plants to cut back the stem include Primula, daylily, iris, and Pulmonaria.
I have all these in my early season garden. Daylilies like Stella D’ Ora will rebloom if you keep on top of deadheading. It is important to not allow seed pods to form to stimulate repeat flowering. Make sure and cut stems back to the crown. The removal of the flower stalks stops seed production. Why this is important?… because the energy goes back into the plant for stronger foliage, not to mention the plants just are more attractive if kept neater.
When Achillea, Shasta Daisy and Salvia is finished blooming, I cut the dead flower off to the next set of leaves. When the stalk gets brown and dry, I remove it down to the base. Growing at the bottom of the cut flower stalk will be new basal foliage. The basal growth will continue to increase for the remainder of the season. Salvia will rebloom, sometimes so will the yarrow. So what happens now with that clump of basal leaves? It leaves a big, short gap in your garden. Since you expect this, just place plants next to, in front of or behind the Shasta Daisy that will either bloom later in the season or will remain tall and bushy, blocking the open gap.
This is a great opportunity to have this group of plants planted with late, fall blooming perennials as plant partners, like Phlox, Aster, Joe Pye Weed or Agastache. I like this group of perennials for their ease of care. Just chop off the dead flowers and leave the green. They stay about the same height so the design remains unaffected.
Coreopsis `Zegreb’ will often rebloom within 2-3 weeks after shearing. I shear them in early August. Long-blooming and bushy, they are nice as bed edging or in front of plants that fade and do not rebloom.
This might be a time to mention something very important in design. Gardens showing perfect displays of perfectly proportioned plants all layered from tall to short is not the way a professional designs if you want beds to have a natural look. It looks great in a magazine, but is too rigid in real life. You want the look you find in nature, a flowing mix of plant heights and textures.
Designers plant early bloomers that will leave holes further back in the bed to be covered by later, taller bloomers after the early group fades. So every thing you heard about having all short plants front and center is not always the way a pro does it. Just look at any well designed public garden and see how they handle perennials that go dormant. Short plants that fade are covered by taller plants so as not to see the gap.
Veronica and catmint are two plants that when they are finished blooming look rather ratty. They become leggy, with older foliage becoming unsightly. Other favorites of the early border such as bleeding hearts and poppies, when they go dormant, they vanish. This leaves gaps in the garden. Some plants, such as geranium, catmint or Veronica look lousy after the big bloom, so what about them? This group I cut back hard for rebloom. If you foliar feed they will rebloom even quicker in two to three weeks. It is up to you how you foliar feed, but for instant results, commercial fertilizers speed things along.
Speaking of early bloomers, what about bulbs? Tulips and daffodils leave a big gap, so you need to think about the perennials bloom time and the size compared to the bulb plants you wish to hide after bloom.
What do designers do? Well, when planting perennials, designers sneak in bulbs to the back of the planting hole. The perennial planted in front of the bulbs will hide the dying bulb foliage. Smart gardening means you to know a plant’s tendencies and needs. Alliums multiply and will need room. They have very unsightly, browning large-leaf foliage while in bloom. Best to make it unnoticed like shown below.
Designers might also inter-plant bulbs with seeded annuals. Since annuals have shallow roots, they don’t really disturb too much of the perennial when planted in front of or beside them. Seeded or planted, annuals and biennials are very useful garden dressers like shown below.
Plants I don’t deadhead include, foxglove, Aquilegia, Delphinium, Verbena bonariensis, flax and the rest of the self-seeding cast of players. Whether annual or biennial, they need to produce replacements. My garden has all of these listed, the Delphinium below in its second bloom spurt. They come back smaller but are a welcomed sight.