I have a “thrive or die” gardening mentality. I prefer rugged species that are hardy in my chilly zone 4 climate, laugh in the face of my less-than-ideal clay soil, and require minimal hand- (or stem) holding. If you’re a perennial that requires daily watering, regular pinching and staking, or lots of general fussing, well, you likely won’t last long in my garden beds.
So when I planted several gladiolus bulbs last year, my initial excitement over the bright orange, tropical-looking buds quickly faded away to exasperation. They were so floppy. They sagged all over my stalwart geraniums. The leaning stems eventually snapped under the weight of the heavy blooms, and well, that was it for me. No glads in my garden this year.
Maybe you’ve encountered flopping perennials in your garden, too. Whether they’re craving more light, less fertilizer, or just naturally have heavy flowers, perennials lean and splay out for lots of different reasons. Don’t let floppy stems get you down! Read on and learn how to keep your garden perennials upright.
Be Supportive
Support tall perennials early with stakes or cages.
Staking is the most obvious solution to fix floppy perennials. Some flowers are just prone to flopping. Species with long stems and heavy flower heads, like delphinium, gladiolus, and hollyhock, may require a little support. Staking works well for these plants that grow taller than they are wide and have just a few top-heavy stalks.
Stake early in the season, when plants are about one-third their maximum size. Stakes are generally thin metal or bamboo, although I’ve had plenty of luck just wandering into the adjacent woods and finding a few rigid, relatively straight sticks.
Insert the stake into the ground near the plant, avoiding the central root clump. Loosely tie the main stem to the stake with twine. If I decide to dive back into the gladiolus world again, I’ll be sure to psyche myself up for some staking first.
For bushier species that send up tons of stems, try a cage or ring-style support. These are typically metal or wire and consist of an outer frame with or without a gridded interior. Peonies, phlox, dahlias, and other wide, multi-stemmed perennials are good candidates for cage supports.
Avoid awkwardly threading individual stems through the support (and potentially snapping them in the process) by setting these supports up early in the season, as new growth is just emerging from the ground. The stems will grow up through support on their own.
Get the Pruners Out
Prune perennials in spring for stronger stems and bushier growth.
Grab those pruners and be prepared to give your perennials a haircut. Cutting back reduces the height of the entire plant, which helps to reduce the weight. You’ll have sturdier stems with bushier growth and more side shoots.
In the spring, once the plant reaches about one foot in height, cut back hard, at least by six inches or one-third of the overall plant height. It will feel counterintuitive to prune so much fresh growth off – but go for it! In addition to stronger, stockier plants, you’ll be able to control the size and shape of the plant, as well as potentially extend the flowering season.
Sedums and asters respond well to being cut back in the spring. However, mounding perennials like moss phlox, heuchera, and hardy geraniums won’t really benefit from a heavy pruning. For these low-growing plants, simply snip away any old, ratty-looking foliage at the base of the plant.
Cut Back On Fertilizer
Use balanced, slow-release fertilizer for healthy, sturdy plant growth.
Fertilizer can be tremendously beneficial for plants that are either heavy-feeders or sited in particularly poor soil. However, an over-fertilized perennial that is already growing in rich soil can produce fast growth at the expense of strong stems. Weak stems will eventually flop over through the season. In particular, too much nitrogen can produce a surge in leafy vegetative growth, without supportive stems or even flowers.
Start with healthy soil that is amended with plenty of compost and topped with a moisture-conserving layer of mulch. If you do need to apply fertilizer, use a slow-release formula that will feed plants a gradual dose of nutrients over several months. Look for a balanced fertilizer that will supply equal parts nitrogen, phosphorus, and potassium.
Of course, there are some perennials, mostly native plants, that don’t really require any fertilizer. Coneflower (Echinacea spp.), blue false indigo (Baptisia spp.), butterfly weed (Asclepias tuberosa), and lavender (Lavandula spp.) all thrive in average, well-drained soil with no supplemental fertilizer. Unsurprisingly, I have a lot of these plants tucked all over my garden.
Provide More Sunlight
Ensure adequate sunlight to prevent leggy growth and flopping.
Another reason for leggy growth and flopping stems? Not enough sun. Plants require sufficient sunlight in order to photosynthesize and grow. If they are sited in a location with inadequate light, they may stretch and bend towards the direction of the sun. They may grow weaker stems with fewer leaves. This innate tracking of the sun, called phototropism, is a way for the plant to optimize their exposure to light.
Understand your garden’s sun exposure before popping plants in the ground. Many plants tolerate partial shade, but perennials like yarrow, blue Russian sage, lavender, blazing star, bearded iris, and black-eyed Susans require a full day (at least 6-8 hours) of sunlight. If you have the space, relocate these floppy plants to a brighter corner of the garden. Shear off about one third of the total plant height, dig up, and replant.
If you have an overgrown tree in your yard, adding more sun may be a matter of pruning a branch or two back. If you live somewhere with larger trees, consulting an arborist is best.
Divide and Conquer
Revitalize overgrown plants by splitting them for better growth.
Dividing an old or overgrown clump of plants can help keep them upright and looking tidy, in addition to managing the overall size of the plant. Perennials in need of dividing may start to produce smaller or fewer blooms, develop a bare spot in the middle of the plant, or flop outward. Breaking up these perennials cuts down on the older, outer bulk of the plant and stimulates new growth from the center crown.
When it comes to dividing perennials, timing is key. Avoid digging up plants when they’re about to flower or during periods of environmental stress like drought or exceptionally high temperatures. Divide fall-blooming perennials in the spring; they’ll have the entire growing season to recover. Divide summer-blooming plants in the fall, at least 4 weeks before the ground freezes to allow ample time for roots to get established. In areas with mild falls, it may be possible to divide fall-blooming perennials with enough time before the first frost.
| Divide These Plants In Spring | Divide These Plants In Fall |
| Asters | Allium |
| Chrysanthemums | Bleeding Heart |
| Shasta Daisy | Irises |
| Sedum | Peonies |
| Turtlehead | Lilies |
| Yarrow | Hostas |
There are some perennials that do not benefit from dividing. These plants should only be dug up if they need to be relocated or removed from the garden entirely. Avoid dividing plants with very deep taproots, like false indigo (Baptisia spp.) butterfly weed (Asclepias spp.) and baby’s breath (Gypsophila spp.).
Woody, shrub-like perennials like lavender and rosemary should also not be divided; breaking up the tough, fibrous roots attached to the crown will severely damage or kill the plant.
Key Takeaways
Stop the flop! There are plenty of tricky garden pests and diseases that are difficult to diagnose and solve properly. Luckily, flopping plants are typically a matter of a plant’s growth habits or your garden’s environmental conditions, and are therefore easy to remedy.
By choosing the right plant type for your sunlight levels, deploying some strategic plant supports and pruning practices, and going easy on the fertilizer, you can have gorgeous perennials that stay standing all season long.
