Foxgloves are beautiful, but all parts of the plant are toxic and so they need to be handled with care. They are fairly easy to grow and are a classic plant for the cottage garden.
Most varieties of foxglove are biennial plants that will produce foliage in their first year. But they won’t flower until late spring or early summer. Sometimes, flower stems will continue to produce blooms later in summer.
What time of year do foxgloves bloom?
The common foxglove Digitalis purpurea mostly flowers early in the summer of their second year. The flower stem grows straight out of the clump of leaves at the base of the plant.
The flower spikes grow about 3-4 feet tall, producing incredibly beautiful clusters of 20-80 flowers. Each downward-facing flower has four lobes that are often speckled, and it is distinctly bell-shaped.
Pink, purple, or white, the flowers have long hairs inside of them and they are heavily spotted, creating a distinctive aesthetic effect. The tubular flowers are great in the garden and freshly cut for the vase.
The foxglove Digitalis purpurea is a biennial plant that has a 2-year biological cycle. Once your foxgloves bloom, the flowering plants produce masses of seeds before they die.
You can collect the seeds and plant them in late summer so that they bloom the following spring. They need light to germinate, so scatter them and don’t cover the seeds with soil.
Once the seedlings are established, thin them so that they are about 18 inches apart. You can replant some of the healthy seedlings at this stage.
You can also leave some of the seeds on the plants and see if they self sow and start the cycle again. It’s very rewarding when they do – and in the right conditions, they will.
When do Perennial Foxgloves Bloom?
We’ve said that foxgloves are biennial, but there is one type of foxglove that is a hardy perennial. The strawberry foxglove, Digitalis x mertonensis, is a very old, early 19th century cross between Digitalis purpurea and Digitalis grandiflora. And it is perennial.
Both types are indigenous to Europe.
According to the University of Wisconsin-Madison’s Horticulture Division of Extension, it was created by gardeners working at the John Innes Horticultural Institute in England in 1925. It has coppery-pink flowers that are bigger than either of the parent plants.
Like Digitalis purpurea, these hybrid foxgloves flower in late spring and early summer. They make an excellent cut flower and they naturalize more easily than the common foxglove.
The strawberry foxglove is hardy to USDA Plant Hardiness Zone 3, so won’t grow everywhere in the U.S.
Factors that affect foxgloves from blooming
Foxgloves are poisonous, but they are also incredibly pretty, and if you are sensible you will avoid any risks of toxicity. Like all plants that we grow for their flowers, they will produce their best show when their growing conditions are right.
Where to Plant
The curator of herbaceous collections and outdoor gardens at the New York Botanical Garden, Adam Dooling, advises that foxgloves can be grown in various different types of settings. These include regular garden beds and borders where you can mix them with perennial flowering plants.
They also work well in wild gardens where planting is deliberately random, and in container displays.
Foxgloves will thrive in light, moist soils that have a high organic content. But, truthfully, they grow in just about any type of soil, as long as it isn’t too dry or too wet.
Ideally, the solid should be slightly acidic. The pH should be between 5.5 and 6.5.
Foxgloves are hardy in USDA zones 3-9. This means that they will do well in areas where the annual minimum temperatures range from as low as -30°F to up to 30°F.
Perennial strawberry foxgloves do best in the lower temperature range. Here, the annual minimum temperatures are no lower or higher than -30°F to -40°F.
But, these are minimum temperatures.
When you grow foxgloves, you need to ensure that they spend 4-6 weeks between the first two seasons in an environment where temperatures are between 38 and 45°F. This encourages vernalization, which is the process of encouraging new flowers.
The best way to guarantee this temperature range is to start them in a greenhouse where you can control the temperature. Or you can move them inside during the winter months while the plants are dormant.
Dooling advises that it’s perfectly acceptable (and safe) to move first-year rosettes during their first season. This will be when they aren’t flowering.
He also says that many outdoor garden environments enable vernalization. So, it may not be essential to move them at all.
Additionally, many new cultivars don’t need this process. This makes them easier for amateur home gardeners to grow foxgloves that always flower.
Ideally, grow foxgloves in sunny spots with areas of part shade. That said, many home gardeners report that they have grown them successfully in full sun.
Digitalis purpurea f. Albiflora, which is an unusual white foxglove, will happily grow in almost complete shade.
Foxgloves need water, but not a lot of it. When the soil gets too dry in summer, and it doesn’t rain, you will need to water your foxglove plants.
A good rule of thumb is to give the soil about 1 inch of water. If the plants get too much moisture, crown rot can kill them before they get to flower. Powdery mildew is also often caused by too much moisture.
This is so obvious that many gardeners overlook it! By planting seeds every year, you will have flowers every spring and summer.
Because they are biennial they live for 2 years and only bloom every second year. By planting every year you’ll have a new set of flowers every year!
Of course, if you plant potted nursery plants that are already in their second year of growth, you won’t have to wait a year before they flower.
How long do foxgloves bloom?
Foxgloves bloom for 2-3 months, usually from late spring until early summer. This means that they will add color to your spring and summer gardens, complementing spring bulbs and summer annuals and perennials.
Once they stop blooming, trim the brown and straggly bits back to just above the green leaves. This will stimulate new green growth and the plant will look attractive for the rest of the growing season, even though it won’t flower again.
Just remember, though, that if you’re planning to harvest the seeds, or encourage self-seeding, you should leave the plants growing for as long as possible, however scrappy they might look.
How do you get foxgloves to bloom?
Foxgloves will do well in full sun but they prefer partial shade. You also need to be sure that your foxglove plants get plenty of water.
The other important factor to ensure that foxgloves flower is just the right amount of fertilizer. Generally, they don’t do well if they get too much fertilizer.
If you have good, rich, well-draining soil you don’t have to add anything. But, if your soil is poor, it’s a good idea to add fertilizer or to mix some compost into the bed.
Spread about an inch of compost around the base of the foxglove plants early in spring. This will encourage healthy growth.
Be careful not to give them too much water.
Why are my foxgloves not blooming?
We’ve said that foxgloves are easy to grow, but many home gardeners find that their foxglove plants don’t flower. The obvious reason that Foxglove Digitalis purpurea isn’t flowering is that it’s still in its first year of growth.
If it is just a young plant, you will see that there are leaves at the base of the plant but no flower spikes. If this is the case, leave it where it is and wait until the next growing season.
On the other side of the scale, older plants will also fail to flower. Pull these up and discard them.
Another common reason for foxgloves not blooming is because they’ve been fed too much nitrogen. This is why it’s so important to be careful with fertilizer products.
What to do if your foxgloves don’t bloom?
If the foliage of your two-year-old foxglove plants is healthy but it’s not producing flowers there are several things you can try.
If you’ve been using a fertilizer, check its composition. Many products contain phosphorus, potassium, and nitrogen. Remember that foxgloves don’t like nitrogen, so if you’ve been using a product that is high in nitrogen, switch products or simply stop feeding fertilizer.
If you’ve watering regularly, try cutting down. Also, make sure that your foxgloves get enough sun.
You might be able to trim back tree branches or overhanging bushes. Otherwise, be more careful next time you plant foxgloves.
One of the advantages of all varieties of foxglove is that they are hardy. This means that they will generally withstand a cold winter and produce their gorgeous tubular flowers in spring.
They are also easy to grow and can be used en masse to create a stunning effect in any style of garden. What not give them a try?