How to Grow Lupines, a Native Plant
I will never forget the first time that I grew lupines. I don’t think that my neighbors will either. They were accustomed to seeing me carefully preparing garden beds, seeding, then watering them. Imagine their surprise when I walked all over the lupine bed after seeding it. The instructions said to step on the seeds to insure good contact with the soil. So I did.
What are Lupines?
Lupines (Lupinus polyphyllus) are a species in a much larger genus, Lupinus. The many lupinus species are found mainly in North and South America. A smaller number are native to the Mediterranean region. Lupines are related to Texas Blue Bonnets (L. texensis), another species of lupinus. The garden lupines with which we are most familiar are actually hybrids known as (Lupinus X russellii hort) because they were bred by George Russell in the UK in 1937. The original lupines were blue. He bred them to be many different colors and to have denser floral spikes than the originals. Interestingly, the blue color is a recessive gene but if you allow your Russell Hybrids to reseed themselves in your garden, within a few years, they will revert back to their original blue color. Russell Hybrids
All lupines are members of the legume family. Like peas, they can fix nitrogen in the soil. They do this thanks to bacteria in the soil which penetrates the roots. When the plant dies, the nitrogen in the roots is released into the soil.
Garden lupines are perennials which are hardy in zones 3 – 7. They grow to 36 inches tall and 18 – 24 inches wide. The leaves are interesting. They look like palm leaves with 7 – 10 leaflets each. The flowers look just like pea flowers but on tall stalks. They come in red, pink, white and yellow and in bicolors. Bloom time is late spring to early summer. The seed pods look like hairy peapods. Each pod holds 12 seeds. Because the plants are hybrids, the seeds will not produce the same color flower as the plant that they came from.
How to Grow Lupines
Lupines will grow in either full sun or partial shade. When grown in partial shade, they don’t flower as well. They are a little fussy about soil. They need well-draining soil because their long taproot makes them subject to root rot if the soil does not drain. Avoid planting them in clay. They prefer loam but will also grow in sandy or rocky soil.
When you first plant them, make sure that your plants are getting at least 1 inch of water each week. A thick layer of mulch will help keep the soil moist and discourage weeds which will compete with your plants for sunlight, water and nutrients. Once established though, lupines are pretty drought tolerant.
You won’t need to fertilize your plants because they are nitrogen fixing. They provide their own fertilizer.
The Russell Hybrids are large plants, so space them 2 – 3 feet apart in your garden.
How to Divide Lupines
Dividing lupines is usually not recommended because they have a long taproot. Plants with long taproots do not like to be disturbed which means that if they are dug up to be divided, they may die. If you would like to try to divide your plants, do it in the early spring before the plant starts growing. Carefully dig it up, trying to get as much of the taproot as possible. Once the plant is out of the ground, you can cut the crown apart and replant the divisions 2 – 3 feet apart.
Another way to divide lupines is by only partially digging up the plant. Just lift the part that you want to make a division from, cut it away from the crown and then gently pat the plant back into place.
How to Grow Lupines From Seed
It is best to direct sow lupine seeds in your garden where you want them to grow. The plants do not transplant well because of their long taproot. Soak the seeds overnight to soften the hard seed coats. Plant them in the fall to germinate the following spring. They should ¼ inch deep. The advice is to make sure that they have good contact with the soil because the soil temperature will tell them when to germinate in the spring. As I noted above, the instructions that came with my seeds said to walk on the soil after sowing the seeds to make sure that they had good contact.
If you want to start the seeds indoors, start them 6 – 8 weeks before your last frost. Soak them overnight then plant them ¼ inch deep. Keep the soil moist. The seeds should germinate in 2 – 3 weeks, or up to a month. Perennial seeds take longer to germinate than seeds for annual plants. You can transplant your seedlings outdoors after your last frost. Space them 2 – 3 feet apart.
© 2020 Caren White