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When to cut back lupins?

When summer is over and autumn begins it is time to start thinking about cutting back your lupins, but when is the right time to cut back lupins? Let’s have a look and find out.

Cutback or Deadhead?

These are two different terms that mean different things. You should be deadheading your lupins throughout the summer whenever the flowers are finished. Cut the flowering spike off and chuck it into your compost heap or garden waste bin.

This will help to promote the growth of new flowering spikes and prolong the flowering period of your lupins.

Cutting back is something you do at the end of the growing season where you cut everything off your lupin right back to ground level. The plant then stays dormant over winter before bursting back into life the following spring.

Lupin in mid spring
Lupin in mid spring

When to cut back lupins

To help your Lupin survive the cold winter nights it is highly advisable to cut it right back to base in late Autumn. While this may seem harsh the plant will be just fine as all its energy will be stored up in the roots. The plant will then be ready to explode back into life come spring, bringing you better than ever growth and flowering.

The timing is really down to you as the gardener, but you want to do it around autumn time before there is any risk of frost.

For most gardeners, this just comes down to an aesthetic decision as once lupins have flowered and the foliage starts dying back they can look quite unsightly. If you like a tidy garden then you can start thinking about cutting them back once the last of the flowers has died.

Lupins in bloom
Lupins in bloom

I like to leave my lupins to grow for as long as possible, the way I see it the more days of light they get on their leaves the more energy they can store in the roots ready for next spring.

Lupins will naturally die back in winter anyway but if you do it before a nasty frost you can reduce the damage done to the plant.

Overwintering your lupins

The vast majority of Lupins will be just fine left outdoors over a British winter. It is worth noting however that pot grown lupins will be more vulnerable to frost, as all pot grown plants are, so moving them into a greenhouse or another sheltered spot is advisable.

The heart of your lupin plant is deep down in the roots so they survive cold spells just fine when left in the ground. When in a pot, however, the heart of the plant is beneath much less soil, particularly from the sides and as such can end up getting frozen.

More on Lupins

Lupins are a beautiful flower that you will find in many British gardens. Lupins are a staple of British cottage gardens, famed for both their height and colour. Originally hailing from the Mediterranean they are a perennial that will greet you with a gorgeous display year after year.

They produce a large flowering spike that is full of colour and each plant can have lots of these spikes leading to a fabulous display. They will begin to flower around may and can last well into June. The flowers do go to seed quite quickly but your lupin will continue to produce more and more new spikes.

To get the best out of these spikes though it is essential to deadhead the old spikes to give the new ones a chance to flourish. Also cutting your lupins back in autumn can help them the following spring. The seeds are edible but if not treated properly first they can be poisonous to animals and humans. Greenfly can be a common problem for lupins here in the UK.

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