Foxgloves: Choosing Compact Spikes or Towering Spires

Match the foxglove to the space you actually have

Foxgloves (Digitalis purpurea) are the plant most gardeners picture when they want a flower spike that keeps rising after other perennials have topped out. The common species and its cultivars form a rosette of soft, downy leaves in the first year, then send up a flowering stem that opens tubular blooms from the bottom upward. Heights vary enormously in this genus, from compact forms of roughly 60–70 cm through the familiar 1.2–1.5 m kinds and on to the taller species such as Digitalis ferruginea. That range is the single most useful thing to understand before you buy, because it decides where the plant sits in a bed, whether it holds its own in a border and how much support it needs.

Foxgloves are short-lived, most often flowering in their second year and then setting seed before dying back. That cycle matters when you are choosing between a compact form for a small patio pot and a tall form for the back of a border: both are genuine foxgloves, but they behave differently in wind, in pots and in a mixed planting, and the size you pick will shape the routine care that follows.

What compact foxgloves are for

Compact selections suit situations where the flower should sit at or below eye level, or where the plant must stay put without stakes. Think of a narrow path edge, a low wall, the front of a border or a deep container on a balcony. A 60–70 cm spike is sturdy, breezy in a light wind without flopping, and readable from a seated position, which makes it a good kitchen-window or patio plant.

Most compact foxgloves suit two growing positions:

• Pots and raised planters, where the whole plant is visible and the rosette can be kept clear of mud splash.
• Front-of-border planting, where they bridge the gap between low ground-cover and mid-height perennials.

Because the flowering stem is shorter, the plant invests less in height and more in the rosette and the number of flowers per stem. A compact form usually gives a denser, more chubby spike, sometimes with a second flush from side shoots if you cut the main stem back after it fades.

What to check when buying compact forms

Look at the actual label height, not the word on the tag. Compact is a loose description, and two cultivars sold as compact may differ by 20 cm. Then check whether the strain is described as a first-year flowering type, because that decides whether you get flowers in the summer after a spring sowing or have to wait for the following season. If you want an immediate display, buy plants in flower and accept that they are nearer the end of their life cycle than a young rosette.

When to choose large foxgloves

Tall foxgloves are for gardens where a vertical, almost architectural gesture is wanted. The wild type and many of the classic cultivars reach 1.2–1.5 m, and in a rich, moist soil with some shade they can push taller. This is the version to plant at the back of a border behind peonies, hardy geraniums or roses, or against a wall or fence where the spike is seen against a flat backdrop.

Height brings two genuine trade-offs. First, tall spikes in exposed ground may need a discreet support, especially when the flowers are heavy with rain, and a single stake or a ring support set in early spring is easier to place before the stem has grown. Second, tall forms are less suited to small pots, because the pot must be large enough to hold the roots and deep enough to counterbalance the stem, and a windy balcony will test both. If you garden in a windy site, choose a tall foxglove only where you can shelter it or stake it.

Tall foxgloves also earn their place in a cutting garden. The long spikes are useful in arrangements, and cutting them often encourages secondary spikes from lower buds. Grow a block of them where they will not shade smaller plants you value.

The routine care both forms share

Foxgloves are woodland-edge plants in the wild, so the growing conditions that suit them are consistent across sizes: light to medium shade, or sun with moist soil at the roots, and a humus-rich, well-drained ground. Airy shade under deciduous trees or on the east side of a wall is close to ideal. Deep shade and baking, dry sun both shorten the flower display.

Watering and feeding

Young rosettes and newly planted foxgloves need consistent moisture while they establish. Once settled, the plants tolerate short dry spells better than they tolerate waterlogging. In a pot, the growing medium dries much faster than garden soil, so check by feeling the top few centimetres rather than following a fixed calendar. A balanced liquid feed every few weeks through the growing season supports the rosette and the developing spike; a very rich feed can produce lush, soft growth that flops, so moderation suits this genus.

Staking and deadheading

Tall forms benefit from a stake set early, tied loosely with soft twine in two places along the stem. Allow the spike to move a little; rigid tying snaps stems in gusty weather. As the lowest flowers fade, you can cut the main spike down to a strong side shoot to encourage a second, shorter flush. Leaving the last flowers to ripen seed is the main way foxgloves self-sow, which is how a colony builds up in a border over a few years.

Managing self-sowing

Foxgloves are generous self-sowers where they are happy. The seedlings appear close to the parent plant and are easy to move while small, but they can crowd perennials if every one is kept. Decide whether you want a drift of them or a single accent: for an accent, pull seedlings you do not need; for a drift, leave a few seedlings in place and lift the rest to new spots.

Compact versus large at a glance

The choice comes down to the planting position and the maintenance you are prepared to do:

• Small gardens, balconies and pots: compact forms are more stable, need less support and read well at close range.
• Border backs and walls: tall forms give the vertical structure that smaller plants cannot, provided they have shelter or a stake.
• Cutting gardens: tall forms give longer stems and more material per plant.
• Low-maintenance planting: compact forms need less staking and less re-tying.

Two or three of each, planted so that the compact ones sit forward of the tall ones, is often the most effective arrangement. The height difference becomes a feature instead of a problem.

Occasional projects worth doing

Foxgloves reward a little extra effort beyond the routine. The most useful projects are the ones that extend the display or build the colony.

Collecting seed to keep a colour form

Named cultivars do not come true from seed, so if a particular colour or form matters, collect seed only from plants that show it, and accept that offspring may vary. Harvest the capsules when they turn brown and begin to split, tip the seed onto paper to dry for a few days, and store it in a labelled envelope in a cool, dry place. Sow the following season on the surface of a moist seed mix and press it in; foxglove seed needs light to germinate, so do not bury it.

Raising plants for next year

A small tray or module insert is enough for a home sowing, and a clear lid keeps humidity up while the seed germinates. Prick out seedlings into individual pots of a free-draining mix and grow them on in a cool, bright spot before planting out in autumn or early spring. This is the reliable way to have foxgloves exactly where you want them rather than wherever they choose to appear.

Extending the display with cut flowers

Cut spikes in the morning with a third of the stem still on the plant so the rosette can recover and produce side shoots. A sharp pair of snips and a clean bucket of water keep the stems in good condition for arranging. Because the flowers open from the bottom up, cut when the lower third is fully open and the top buds are still tight.

A practical planting decision

Buy compact foxgloves when you need a plant that holds itself up and can be enjoyed from close range, and choose tall foxgloves when you want a vertical accent and can give the plants shelter or support. Check the labelled height, the first-year-flowering habit and the site conditions, then plant the rosettes so the crown sits at or just below soil level in moist, humus-rich ground. Whatever the size, the same routine keeps them looking well: steady moisture, modest feeding, an early stake for the tall kinds and a decision about how many seedlings to leave. Foxgloves are not for every garden, partly because all parts of the plant are toxic if eaten, so place them with children and pets in mind and wash your hands after handling cut stems.