This Is the Ideal Height to Get Supports in Place for Your Flowers – Act Quickly, or You Could Risk Damaging Plants
Discover when to support perennials for healthy plants and beautiful displays
Supporting tall or top-heavy perennial and annual flowers is a crucial task early in the season. Knowing when to support perennials and other flowering plants ensures you get your supports or stakes in place at the perfect time to keep them safe.
Acting fast in spring is always the best course of action, ideally when the flowering perennials are 6-12 inches tall. This is a crucial moment to support flowers, as it gives them time to grow naturally through the structure and avoids causing unnecessary harm, which can all too easily happen if you try to put supports in later.
To help you understand when to support perennials, I spoke to two gardening experts about the size plants should be when you put supports or stakes in place in spring, along with the potential damage you can cause if you do it too late. You’ll see why supporting perennials needs to be on your spring gardening checklist.
Article continues belowWhen to Support Perennials – This Is the Best Time
It is well-known that you need to support flowers early. Acting sooner in the season is always the best practice, as it prevents causing damage by trying to install supports further down the line. Early-season action to support flowers also helps hide the supports themselves in the flower bed.
Staking or supporting perennial plants is vital to prevent stems from dropping or flopping, especially under the weight of heavier blooms. It also stops stems from snapping during strong winds. While supports are important, you don’t want them to harm or take away from the plant’s beauty – an ideal support will aid but not stand out.
This is why Jessica Mercer, Horticulturist at Plant Addicts, advocates for putting supports in place in spring, while the plants are less than 12 inches tall.
‘It is better to install plant supports early because the stems grow up through them and hide the structure as they fill out,’ she says. ‘The support becomes part of the plant and distracts less from the view.’
If you support flowers near the start of the plant's active growth in the spring, it also makes it easier to train or tie stems as required. Aim for that critical period when the plant reaches 6-12 inches tall, when the fresh growth is more amenable.
‘At this stage, the shoots are still young and flexible, so they can be easily guided where needed,’ says Halina Shamshur, resident botany expert at Plantum. ‘Plants are also still relatively short, making them easier to manage.’
The message is clear. If you are growing tall, top-heavy, or thin-stemmed flowering plants to stake, including delphiniums, peonies, dahlias, sunflowers, black-eyed Susans, or asters, then get your supports in early in the season. It is an important time to keep them looking at their best and undamaged for the season ahead.
Jessica Mercer, PhD, is the Senior Content Marketing Coordinator and plant expert for Plant Addicts. As a 'plant collector', Jessica enjoys growing many different plants and learning about the best cultural practices for each. Writing for Plant Addicts is a real joy for her, as she can use her science background to research interesting plant topics. She carefully considers how to best present the information to other gardeners, with a focus on sustainability and the environment
Halina Shamshur is a resident botany expert for the Plantum app, which helps users identify plant species, diagnose their conditions, and get specific care advice. She has 25+ years of experience as a professional botanist and 5 years of experience consulting on botany-related topics for Plantum.
The Damage You Can Do by Putting Supports in Later
As mentioned, staking later in the season is not advisable, as trying to support flowers once they have put on lots of lush growth is not only more difficult but increasingly likely to damage roots, stems, and leaves.
Putting canes or supports into the ground once a perennial is established risks piercing the root ball. Halina Shamshur warns that installing supports at the wrong time can ‘seriously harm the plant’ and set it back, or even worse.
‘Driving a stake into the soil next to a well-developed plant can severely damage the root system,’ she warns. ‘The later you install a support, the larger the root system will be, and the greater the risk of harming major roots.’
When contemplating the worst-case scenario, Halina adds: ‘Significant root damage can even lead to plant death.’
It is not just the roots that are more at risk of damage, as Jessica Mercer foresees a greater likelihood of gardeners mistakenly ‘jabbing’ the support into bulbs or the crown, as they all expand during the season.
Those risks are all on top of damaging top growth in the form of flowers, leaves, and stems by wrestling with developed plants, trying to support plants during the prime growing season.
Shop Plant Supports
This sleek black metal plant support is strong, durable, and weatherproof. It is 36 inches tall and 21 inches wide to support a wide range of perennial plants.
These three-legged plant cages are suitable for peonies, as well as any other tall flowering perennial. You get eight 12 x 15.7-inch plant supports in a set.
An obelisk is perfect for climbers. This wrought-iron example measures 61'' H x 13'' W and can bring elegant vertical growing into any flower bed or large container.
FAQs
How Should You Support Flopping Flowers?
There are some flowers notorious for flopping, such as peonies, delphiniums, shasta daisies, and tall phlox. Ideally, any flowers are supported in early spring once the growth is under 12 inches. However, you can support them once they have flopped, provided they are not damaged. As Jessica Mercer from Plant Addicts warns: ‘Blooms that have been lying on the ground too long are often splashed with soil or damaged beyond any repair with staking.’
When flowers have dropped but aren’t too damaged, carefully lift them from the ground and add hoop supports, such as these metal plant supports at Amazon, taking care not to jab the it into the roots or the crown. Alternatively, individual stems can be gently tied to a carefully placed bamboo stake with string, soft twine, or soft plant ties (like these soft plant ties, also at Amazon).
When I worked in open gardens in the UK, it was common to build plant supports from hazel stems. These supports or cages looked natural and blended in with the foliage among the flower beds. If this inspires you, our guide to building hazel plant supports talks you through the process of making natural structures for your perennials or flowering climbers.
If you love inspiring garden ideas, outdoor advice, and the latest news, why not sign up for our newsletter and get the latest features delivered straight to your inbox?
