Our site is reader supported, this means we may earn a small commission from Amazon and other affiliates when you buy through links on our site.
Last updated on January 21st, 2020
Lupin flowers are some of the most breathtaking of colours. They have stiff, erect spikes from which flowers are produced and the fan-shaped foliage emerges horizontally. The flowers are very similar to flowers you would find with sweet peas as they grow in densely packed groups the colours for which range from pink to white, deep blue, purple, even yellow.
This is a fairly long-lived perennial which does not require a great amount of care except for deadheading to promote more flowers, do this as soon as the flowers fade. Realistically they just need a sunny spot, well-drained soil, ample water when newly planted, and after that you get to sit back and relax and just deadhead now and again. They make for terrific additions to any borders or scattered throughout your native landscape but as they can grow fairly tall, reaching as tall a 5ft, they are best planted towards the back or middle of flower beds.
They will typically bloom sometime between early spring through the first part of July which is why it is recommended that you plant them with other late-blooming summer flowers so that you get ample colour throughout the growing season.
Lupins are known as being dear resistant
If you leave an area where deer are problematic, Lupins are also known to deer resistant as concluded from a survey of the gardening public’s experience by the RHS.
Attractive to bees and butterflies
The flowers will bring many visitors to your gardens such as butterflies and bees.
Garden gold: a bit of these plants will improve the fertility in your soil overtime because they fix nitrogen levels which improve the soil. If you have poor soil lupins can be grown from seed direct around April and used as green manure by digging them into the soil around September after flowering which will improve nitrogen in the soil.
The most common colour you will find for your flowers as purple followed closely by blue, yellow, pink, and white varieties but you often also get mixed colours because if grown from seed, they very rarely come true too colour. They also prefer cooler areas with an average pH level in the soil but grow well in acid, chalky or neutral as long as it’s well drained.
When you plant them you should do so in full sun or light shade and make sure that you loosen the soil deep into the ground so that the taproot is able to grow properly.
|Sunlight||Full sun to light shade|
|Maturity||Blooms between July and August|
Taking cutting, sowing seed and dividing
You can grow these plants from seeds which often don’t grow true to colour, from basil cuttings which is by far the best and most successful way and guantee what flower colour you will get, or from divisions which can be tricky but also guarantees the colour.
If you are growing from seed the germination is increased greatly if you give it a 7-Day cold treatment. For this, you place the seeds inside of damp paper towels and place the paper towels inside a ziplock bag. Place the bag in your refrigerator and leave it there for 7 Days. An alternative method is to soak the seeds in warm water for 24 hours prior to planting. Treated seeds can be sown directly into the ground in spring or summer until the start of August. It is best to plant untreated seats however outside between September and November. If you plant from seed it will bloom the first year and you should pinch off spent flowers to elongate the blooming time you get.
Important note – seeds do not usually grow true to colour so you usually get mixed colours
Taking basal cutting
If you are growing from cuttings, you should take a stem from the plant all the way to the bottom of the trunk, as far down to the root as possible. Pinch the tops out, they should be stubby little shoots. Place the cutting and moist, well-drained soil, very gritty soil is best. Keep it covered while it propagates but give it some ample airflow for a few minutes each day so that the plant adjust properly, if you have a greenhouse just pop them in there uncovered instead and water well. Start your cuttings in larger pots which you can easily transplant outside without disturbing the roots, 3 cutting in a 5-inch pot is usually about right. As long as your taproot remains delicate, do not transplant because your plant will become damaged and fail, once you see roots appears out of the bottom of the pot you can plant them out.
Dividing plants is not recommended as it can be difficult as they have a long taproot. However, if you want to divide plants you need to do this in spring and never in autumn as this will almost certainly kill the plant.
These plants are very easy to grow and will thrive in cool locations but because they have tall flowers they are best planted in a sheltered position where the wind will not snap the flowers.
They prefer full sun to light shade as mentioned in most soil types even clay soil but you will need to improve the soil to help them get through winter. Once established they will tolerate dry soil as they have very long tap roots and can get water from deep down into the ground. As lupins develop very long taproots, it is important that before you plant you make sure to loosen up the soil very deeply to allow the taproot ample space. In order to promote a healthy plant with large blooms, you should apply organic fertilizer once per month but this is not essential.
Lupin diseases & pests
There are not many pest problems associated with this plant. Occasionally it will become infested with aphids, usually greenfly in which case you can pinch or prune off the heavily infested stems of the plant.
You can also purchase ladybugs commercially which are natural predators. As a last alternative, you can also use a pesticide if you are facing a very heavy infestation.
A problem many people face with lupins is with a fungus called powdery mildew as pictured above, especially in areas where it can be damp or when we have prolonged weeks of rain. The best course of action is to remove affected leaves and spray with a fungicide. Improving air circulation but removing some leaves will help prevent it too