Lupins are considered a classic cottage garden plant. They are available in a variety of colours incuding red, yellow, pink, white and purple. Lupins bloom during May and June filling the flowering gap between the early spring blooming bulbs and the summer flowering perennials. Lupins are rich in nectar and are great for feeding domestic and wild bees. The tall spires of blooms add architectural interest to your garden landscape. As they can look a bit messy after they flower, it is best to plant them along with other perennials that will take over when the lupins are finished blooming. Some companions to consider are leafy cannas, dahalias or Japanese anemones.
Lupins like a moist, well drained neutral to acidic soil. Plant in full sun. A layer of mulch will help keep the soil moist but do not place the mulch too close to the crown as it could cause rotting over the winter.
To propagate lupins, take cuttings in the the spring. Put them in pots until they root. In autumn, dig up and split plants discarding the centres and replant. Care must be taken when transplanting as lupins have a long taproot. The best time to plant lupin seeds is between September and November. These can be sown directly in the ground. They will take several months to germinate and should produce flowers the following spring.
Lupins can be effected by lupin aphids. The stem will become solid with the aphids that effect only lupins and do not spread to other plants. You will notice the shiny honeydew on the lower leaves. The best thing to do is nothing at all. When populations become so dense, they beome prone to disease. In the case of these aphids, they are prone to a fungus which hopefuly will wipe out the colony. If you must do something, your best bet is to mist the lupins with water in the late afternoon. This will provide a better environment to grow the fungus and hopefully eliminate the colony. The other alternative is to cut the infected plants to the ground and cut them again in September to prevent the aphids from overwintering in the ground. I do not recommend spraying the plants with an insecticide as it will affect pollinators.
I encourage you to consider including this colourful, dramatic and useful perennial in your garden landscape.