Colourful and refreshing Lupin plants are almost everyone’s favourite and, of course, bumblebees love them. This plant grows at its best under full sunlight, but they are known to grow in partial shade.
Overall, the Lupin plants have a relatively short lifespan and will only flower for around 5-6 years before becoming unproductive after which, the taproot will need dividing to provide another 5 flowering years.
Lupin flowers bloom at their maximum from May to June and start fading quite soon after. Once the plant has died completely, it cannot regrow on its own. This is why you need to prune and cut it back so that it may regrow and live further. But do you cut back Lupins in autumn?
What to do With Lupins After Flowering?
If we talk about Lupin cutting season, it is best to cut back faded Lupin flowers all the way to the base in autumn to prepare the plant for the next season’s growth. Lupins should also be pruned throughout the summer to extend the flowering season.
Given below is a basic guide on how to prune lupins to ensure that they continue to bloom all the way through the summer.
Pruning Lupins – Step-by-Step Guide
Just cutting back Lupins in autumn does not count as adequate care. Instead, you need to prune your plant regularly too.
Sufficient care and regular cutting help your plant grow faster and taller, making your home garden a sight to behold. Speaking of pruning, Lupins can be pruned in two ways: deadheading and regular pruning.
Deadhead pruning, or simply deadheading, refers to pruning the Lupin plant once around 70% of its flowers are dead. Deadheading requires extreme expertise and careful cutting on your part, so you do not permanently damage the plant.
Given below are the steps to deadhead or cut back the faded Lupins in the most effective manner:
For starters, make sure that around 70% of the flowers on your Lupin have faded. We do not recommend deadheading the plant if there are still a considerable number of blooming flowers on it.
Carefully cut the stem just above the first side-stem. The primary stem will not grow back but the side-stem will continue to grow and flower later in the season.
Find another stem with faded flowers and repeat the same cutting process.
Once all the flowers have faded, you should cut back the entire plant to the newest basal leaves.
The flower may bloom again, and if it does, repeat the process.
Other than cutting back the faded stems, you may also want to prune the plant to keep it away from infections. Lupins are extremely sensitive to sap-draining aphids.
How to Prune Aphid Infected Lupins
Pruning regularly and keeping a check at your plant can help you detect where the aphid infection is springing. Once you locate the earliest signs of infestation in your Lupin stems, taking the following steps is the only way to save the plant:
Locate all the stems showing any symptoms of infections and overrunning.
Start cutting each one of those located stems. Make sure to cut them back to the very bottom.
Carefully dispose of every infected stem, preferably by burning, do not add infected stems to your compost pile!
Once you are sure that all the infected stems have been removed, take a closer look at the leaves. Try locating any symptom of infection on the leaves and if there is one, cut that leaf immediately.
Carefully check all the stems housing the infected leaves as well as their neighbouring leaves to make sure that they are not infected. Do not hesitate to cut back any stem or leaf even if you sense a meagre infection.
Tips for Effective Pruning
Even when it is helpful, pruning would not do much for your Lupins unless you do it very carefully. Given below are some general Lupin care and pruning guides. Following these during as well as after pruning makes sure that your efforts on your Lupins do not go to waste.
- Always use sharp and fresh blades (amazon link – opens in a new tab) and other tools for pruning. Old tools not only come with rust risks but also make it hard for you to cut back the stems precisely. This can sometimes result in permanent plant damage.
- Make sure you wipe your tools after cutting back every stem. This ensures no transfer of germs and infections from one stem to another, helping the plant stay healthy.
- Never let the removed parts of your Lupin stay around it or any other plant. Rather, you should always dispose of the removed parts properly even if they are not apparently infected. This resists the spread of any undetectable microbe or infection that can otherwise ruin an entire plant within days.
Other than these, watering the plants regularly in required amounts and making reasonable arrangements to save them from harsh weather can also have pleasant effects on your Lupins.
“Do you cut back Lupins in autumn?” Well, yes once the plant has died back in the autumn, lupins should be cut back to the base to prepare the plant for the winter and new growth in the spring.
With the proper cutting techniques, you can keep the plant blooming better for longer. Fully bloomed Lupins can add a lot to the beauty of a place. Hence, with all this effort, you are doing your garden a favour that you would yourself enjoy.
Garden Doctor Tips
“Cut Lupins all the way back to the base in the autumn when all of the flowers have faded, and the plant has withered and died!”
“As with all pruning, ensure that your blades are clean and sharp, and your cuts are true!”
“Do not deadhead the last flowers of the season if you want to harvest the seeds however, lupins do not grow true to type from seed!”
“To extend the life of your lupins, separate after 5 or 6 years when the plant has become woody and unproductive!”
Frequently Asked Questions
Should lupins be cut down after flowering?
Lupins should be deadheaded after flowering to enable fresh growth and prevent the plant from producing lots of seeds.
At the end of the summer, lupins can be cut back to prepare them for winter.
Do lupines come back every year?
Lupines will flower for approximately 5 years before the plant becomes woody and unproductive. To extend the life of your lupins, divide the taproot after 5 years and re-plant.
What do you do with lupins after flowering UK?
After flowering, lupins can be deadheaded to enable growth on the flowering side-shoots. Once all flowers have faded and the plant dies off in the autumn, the plant can be cut back to the base.
When can I cut back my lupins?
It is best to cut back lupins once the flowers have begun to fade. When at least 70% of the flowers have faded, cut back to just above the highest side-shoot which will then begin to flower therefore extending the flowering period.
Are lupins poisonous to cats?
Yes, Lupins are mildly toxic to cats, but not usually deadly.
Symptoms of poisoning include vomiting, tremors or convulsions, swelling of the throat that can lead to suffocation, elevated heart rate and fever. Pets can experience kidney damage if they ingest toxic levels of lupins although it is rare for a cat to eat enough to cause this problem.