Staking Tall Flowers: Supports That Keep Stems Upright

A summer storm passes and the best plants in the bed are lying flat: spires snapped, heavy blooms face down in the mud. Propping them up afterward rarely looks right, because bent stems do not straighten and a bundle tied to a post looks like a rescue.

Staking tall flowers works when it is done early and quietly, with the right kind of support for the shape of the plant. It also helps to reduce how much support plants need in the first place.

Which plants tend to need support

Three groups flop most often:

• Tall spires. Delphiniums, foxgloves and hollyhocks carry a lot of flower on one tall stem that catches the wind.
• Heavy double flowers. Peonies, tall dahlias and large African marigolds have blooms that fill with rain and pull the stems over.
• Lanky clumps. Many perennials grow soft and tall in rich soil, in windy spots or in part shade, where they lean toward the light.

These plants are examples of shapes, not a planting list. Whether any of them suits your garden depends on your climate and hardiness zone, so check the tag. Mature heights are ranges that vary by variety and growing conditions.

Prevention comes first

Sturdy plants need less hardware. Before buying supports, look at the causes of weak growth:

• Enough sun. A plant that wants full sun grows stretched and floppy in shade.
• Restrained feeding. Heavy feeding, especially in soil that is already rich, produces tall, soft stems. Feed according to a soil test and the product label.
• Correct spacing. Crowded plants stretch upward and lean on each other. See the guide to spacing flowers correctly.
• Compact varieties. Many tall flowers come in shorter varieties bred to stand without help.
• Shelter. A fence or hedge on the windward side reduces buffeting.

Cut back late bloomers for sturdier growth

Certain perennials that flower in late summer or fall can be cut back by a third to a half in late spring to early summer. They respond by branching, which gives shorter, bushier plants with more, slightly smaller flowers a little later than usual. The technique is often called the Chelsea chop.

It suits plants that branch freely, such as asters, tall sedum, garden phlox and bee balm. Do not use it on plants that send up a single flower stalk, such as delphiniums, foxgloves, peonies or daylilies, because removing that stalk removes the season’s flowers.

Choose the support for the plant’s shape

How to put each support in

Single stakes

1. Push a bamboo cane or slim stake firmly into the ground 2 to 3 in (5 to 8 cm) from the stem, behind it as seen from the front of the bed. Take care not to spear the crown, bulbs or tubers.
2. Tie the stem with soft twine or a strip of cloth in a loose figure eight: one loop around the stake, a crossover, one loop around the stem. The crossover cushions the stem and lets it move a little.
3. Add more ties as the stem grows, roughly every 12 in (30 cm).

Hoops and grids

Set the hoop or grid over the clump while shoots are only a few inches tall and push the legs in firmly. Stems grow up through the openings and leaves soon cover the frame. Raise adjustable types as the plant grows.

Twiggy branches

Push branched prunings, often called pea sticks, into the soil around and among the young shoots, with the twiggy tops a little below the plant’s expected height. Growth weaves through and hides them. It is the most natural-looking option and costs nothing if you have shrubs to prune.

Stakes and twine

For a group, set four or more stakes around the outside, then run twine from stake to stake around the perimeter and diagonally across the middle. Add a second tier higher up as plants grow.

Timing and height: the two rules that matter

Put supports in early. The best moment is while plants are short, soon after growth starts for the season. They then grow up through and around the support and hide it, and you avoid damaging roots and stems later. A good prompt is to add them during your routine spring flower garden tasks. For more on timing, see the perennial maintenance guide from Iowa State University Extension and Outreach.

Stake to about two thirds of the final height. A support that stops below the flowers holds the stem where it needs holding and disappears into the foliage. For a spire expected to reach 6 ft (1.8 m), that means roughly 4 ft (1.2 m) of stake above the ground. Very heavy flower heads sometimes need a tie just below the bloom as well.

Check, adjust and store

Look over supports every couple of weeks in the growing season. Stems thicken, and a tie that was loose in spring can cut in by midsummer, so loosen or replace any that are tight. Tuck stray stems back inside hoops and add twine where a clump has outgrown its corral.

If a plant has already gone over, support it gently where it lies instead of forcing it upright, and plan a proper support for next season.

At the end of the season, pull out stakes, hoops and twine, brush off the soil and store them dry. On your garden plan, note which plants needed help. Placing tall plants toward the back, where neighbors help prop them, is part of planning a layered flower border.