How to Stop Rhubarb From Flowering and Keep Stalks Thick All Season

For maximum rhubarb harvest, keep the clumps from bolting. Heat can play a part in this, so keeping soil temperatures cool and adding organic matter (compost or well rotted manure) to the planting site will assist.

Older varieties may be more susceptible to flowering, and regularly dividing rhubarb crowns should help.

1. Cut the Stalks Early

Rhubarb flowers are an indicator that the plant is trying to reproduce through seed production; this process is known as bolting. Although flowering is part of its natural cycle, gardeners who want thick rhubarb stalks suitable for pie-making or other culinary uses may find this undesirable.

Rhubarb plants that produce flowers waste energy on seeds that won’t be eaten; their leaf stalks contain toxic levels of oxalic acid. Cutting flower stalks as soon as they appear is an effective way to ensure its resources go into producing thick, flavorful stalks instead.

Weather, variety, plant maturity and overcrowding are all factors which may trigger rhubarb to flower. To reduce its chances of blossoming and prevent flowering altogether, keep it well-tended by adding compost, well-rotted grass clippings or rotted manure and watering regularly throughout summer. Feeding an organic-based fertilizer such as Tui Sheep Pellets in spring will promote leaf growth while discouraging bolting.

2. Remove the Stubs

Rhubarb flowers indicate that its plant is trying to reproduce itself through seeds. Although this process is normal, this takes up energy that could otherwise go toward producing thick stalks of rhubarb. By cutting back or cutting away flower stalks you can redirect that energy towards creating delicious tart stalks instead.

Once removed, there may be some remnants left from where the flower stalk once stood. You can allow these to continue growing longer before taking action to eliminate them; but sooner is better!

Know when it’s time to stop pulling rhubarb. Over-picking can harm the plant, so with practice you’ll learn when and how much rhubarb stems should be harvested at any given time for maximum yields. Select healthy-looking stems before cutting close to the ground so you don’t remove too much all at once, leaving time for recovery of plants.

3. Leave the Stubs on

Rhubarb flowers may be eye-catching, but their high levels of oxalic acid make them unfit for human consumption. By harvesting flower stalks as soon as they appear, we can prevent our rhubarb plants from going to seed and focus their energy instead on producing thick edible stalks that we can consume ourselves.

Flowering is an integral part of any plant’s lifecycle, but certain factors can accelerate this process more readily than others. Heirloom varieties tend to flower more than modern hybrid cultivars. Heat or extreme cold can also induce flowering; poor soil, drought or overcrowding may even trigger bolting as an early onset symptom.

As soon as your rhubarb starts flowering, cut off its flower stalks using sharp knife or pruners such as these Felco F6 Hand Pruners from Amazon as soon as they appear – this will prevent its energy being spent producing seeds or leaves that don’t provide as much nutrition.

4. Remove the Leaves

Plants require energy and resources to produce flower stalks and seeds, so if you are growing rhubarb for its edible stems, cut off flowers immediately with sharp, clean pruners such as these Felco F6 Hand Pruners from Amazon so the plant can focus its resources into producing these highly prized stalks instead of producing new blooms.

Rhubarb leaves also contain oxalic acid which can be dangerous to human health, so removing them altogether is recommended. If you intend on reusing them as medicine, make sure they have been completely purified of all oxalic acid by pulling away from their root crown and peeling back any papery outer layer before use.

To prevent rhubarb plants from bolting, place a large container over their crown and shade from light (such as a garbage can or special terra cotta “forcer”). Additionally, mulch around their bases and side dress them with an organic rich compost or balanced (10-10-10) fertilizer in early spring. Finally, to maintain health for mature rhubarb plants it may need to be divided to allow their roots to reach nutrients more easily and reach deep within their soil environment.