Delphiniums usually do best when planted in the ground but they can also be grown in suitable containers.
One problem with growing delphiniums in pots is that their roots are sensitive and don’t like being crowded.
Another problem is that these plants can get pretty tall, making them more likely to fall over or be blown over by strong winds. As Home Farm Plants owner
“If you grow delphiniums in pots, make sure the pot can drain well because they don’t like being wet.”
“The pots still need to be staked, but be careful not to put them on a patio or other hard surface because they could blow over.”
You can make them look great in a container garden, though, if you know what you’re doing. Some may even make nice cut flowers.
People in the UK grow two main types of delphinium, and both can be grown in pots or other containers:
Delphiniums are treasured garden plants, prized for their tall spires of vibrant flowers in shades of blue, purple pink and white. Their blooms add a whimsical cottage garden feel. While delphiniums are typically planted in flower beds and borders, did you know you can also successfully grow these beauties in pots and containers?
Container growing opens up new possibilities for placing delphiniums in small gardens, on patios, or anywhere space is limited. With the right care and conditions, potted delphiniums can thrive and put on a stunning floral display. Here is a complete guide to growing delphiniums in pots.
Choosing the Right Container
The first step is selecting an appropriate container Here are the key factors to consider
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Size – Go for at least a 12-16 inch diameter container. Delphiniums have deep taproots and need sufficient depth for root growth.
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Drainage – Drainage holes in the bottom are essential to prevent soggy soil. Delphiniums hate wet feet.
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Material – Use plastic ceramic concrete or wood. Metal conducts heat too much.
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Stability – Pick a heavy pot that won’t easily blow over once the tall flowers are growing.
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Aesthetics – Make sure the pot fits your style and decor. A decorative container can showcase the flowers.
Getting the Right Soil Mix
Delphiniums prefer nutrient-rich, well-draining soil. A quality potting mix is ideal for containers. Look for a mix containing:
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Peat or coco coir – Helps retain moisture but resist compaction.
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Perlite or vermiculite – Lightens the mix and improves drainage.
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Compost – Provides nutrients for healthy growth.
You can make your own mix by combining equal parts peat moss, compost, and perlite or vermiculite. Commercial cactus and citrus mixes also work well.
Selecting a Variety Suited for Pots
With hundreds of delphinium varieties, choose compact types under 3 feet tall. Tall delphiniums become top heavy in pots. Recommended pot-friendly varieties:
- Delphinium grandiflorum ‘Summer Stars’
- Delphinium grandiflorum ‘Summer Skies’
- Delphinium grandiflorum ‘Summer Nights’
- Delphinium ‘Blue Bird’
- Delphinium ‘Magic Fountains Cherry Blossom’
- Delphinium ‘Magic Fountains Dark Blue’
These stay compact with prolific blooms on strong stems perfect for containers.
Planting in Pots
When transplanting delphiniums into pots:
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Gently loosen the root ball if rootbound and untangle circling roots.
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Place in pot with the crown right at soil level, not buried.
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Backfill around roots with potting mix, tamping down gently.
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Water thoroughly until it drains from the bottom.
Let plants recover for a few days before moving pots into their permanent spot.
Caring for Potted Delphiniums
The main care tips for container delphiniums include:
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Watering – Check soil daily and water when the top inch is dry. Don’t let pots completely dry out.
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Fertilizing – Use a balanced liquid fertilizer every 2-3 weeks during the growing season.
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Sunlight – Place pots in full sun to part sun. At least 6 hours of direct sun is ideal.
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Temperature – Move pots to a sheltered spot if temperatures exceed 85°F.
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Pruning – Remove spent flower stalks and any diseased foliage.
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Overwintering – Move pots to an unheated garage or cellar before first frost.
Troubleshooting Common Problems
Watch for these potential issues with container delphiniums:
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Leggy growth – Caused by insufficient sunlight. Move pots into a sunnier location.
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Leaf scorch – Leaf tips turn brown when allowed to dry out. Water more consistently.
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Powdery mildew – White fungal coating on leaves. Improve air circulation and avoid wet foliage.
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Aphids – Small sucking insects cause distorted growth. Wash off with water or use insecticidal soap.
Combining Delphiniums with Other Plants
One benefit of growing delphiniums in containers is combining them with other flowers, herbs, and foliage. Some good companion plants include:
- Catmint
- Lavender
- Coral bells
- Lungwort
- Ferns
- Snapdragon
- Poppies
Choose companions with similar light and watering needs that complement the delphiniums’ purple and blue hues. You can create beautiful mixed planters.
Enjoying Delphiniums on Your Patio
The gorgeous blooms and vertical form of delphiniums make them ideal for container gardening. With a large pot, quality potting mix, proper care and a compact variety, you can successfully grow these classics on a patio, balcony or entryway. Potted delphiniums bring elegant flare to outdoor living areas.
Best Container Varieties
If you want to grow perennial delphiniums, the Magic Fountains series is a good choice.
These are smaller delphiniums that will grow to be 75–90 cm tall and spread out to form clumps of 0. 1-0. 5m.
There are a number of different colours within this range that you can choose from.
If you decide to grow annual delphinium, or larkspur, you might consider:
- Delphinium grandiflora
- Delphinium ajacis
They’re cheap and easy to grow from seeds, and they look great in patio pots, window boxes, or even hanging baskets.
They tend to be a little tougher and easier to care for than their perennial cousins.
“Species like Delphinium grandiflora still have flowers that haven’t been grown to be bigger and often double,” says Colin Skelly.
Because of this, they have the shape of a dolphin, which is how the genus got its name (delphis, which means “dolphin” in Greek). ”.
Both perennial and annual delphinium like a sunny and sheltered position.
When you put your potted plants somewhere, you should carefully consider where they will be most comfortable to care for and where the wind won’t hurt them.
Don’t forget to think about the plants’ water needs and how you’re going to meet them. Also, pay attention to things like shade and sunlight.
Also consider other plants in your garden – as well as man-made structures and how these affect conditions.
You might grow delphiniums in their own containers, or in larger containers as part of mixed planting schemes.
When plant roots can’t talk to each other, you should still think about how the plant you choose for a container will work with the other plants and wildlife in your garden.
Containers for delphiniums, especially taller perennial types, should be heavy and stable.
Once you find a safe place, be sure that the pots and containers you choose won’t fall over when tall plants like delphiniums are inside them.
Make sure you pick a pot that is the right size for your plant(s) and keep potting them up until you have the right size container for your delphiniums.
Delphiniums do need water when it’s dry, but it’s also important to make sure the soil in the container can drain freely.
That means picking a container with good drainage holes at the bottom. It might also help to raise the containers off the ground so water can always flow out freely.
In addition to needing a growing medium that stays moist but drains well, delphiniums are also very hungry plants that will need a lot of nutrients.
For this reason, it is important to choose a fertile growing medium.
Choose John Innes No. 2, or any good quality multi-purpose peat-free compost with added John Innes, or another loam-based mix.
Add grit added to improve drainage, and place crocks at the base of the pots.
Sowing and Planting
In the spring, perennial delphiniums are usually bought as plug plants. In the summer, they are bought in pots and are ready to be planted outside.
There are also seeds for sale, but not all types of perennial delphiniums can be grown from seeds.
Plant out these types into your containers in spring or early summer to give them the best chance.
You can plant out at any time, though, as long as you give the soil enough water and keep it from freezing or becoming too wet.
Replant at the same level as the plants were at in their previous pot, and water in well.
Annual delphiniums (like some perennials) can be grown from seed.
You can plant the seeds in the spring or fall to get flowers earlier. In the spring, you can pot them up and put them in their containers for summer blooms.
Delphiniums grown in pots.
FAQ
Do delphiniums like sun or shade?
Do delphiniums come back every year?
How do you keep delphiniums blooming all summer?
Can delphiniums grow in pots?
Delphiniums have intricate root systems that require adequate space to thrive therefore you have to pick a sizeable container to grow them successfully in pots. Below, I will point out how to pick the right container and follow with how to plant and how to take care of your Delphiniums as well as a few issues to look out for.
How do you grow a Delphinium in a container?
Try and stake it early on. It is easier to place the cages and stakes on with less risk of bending and snapping the stalks of flowers. Also for container grown delphinium try and find green stakes or cages, or natural bamboo stakes.
Are delphiniums easy to grow?
Offering towering flowers and vivid colours, Delphiniums command their space in the garden with ease. These plants grow in beds and borders but can also be grown successfully in large pots. They may look like a lot of work, but they are quite easy to grow, as I will show in this guide.
Can delphiniums grow in clay soil?
Clay soil is too heavy and will hold onto water. If delphiniums are sitting in standing water, their leaves will be yellow and they can develop root and crown rot. Sandy soil cannot hold onto water and your delphinium will dry out too quickly. Sandy soil also doesn’t provide much nutrients for the plant to grow.
Can delphiniums be planted in the ground?
Graham Austin is a Delphinium expert and RHS 2022 Gold Medalist who is the owner of Home Farm Plants, a specialist plant nursery. Delphiniums usually do best when planted in the ground but they can also be grown in suitable containers.
How do I choose a potted Delphinium?
Pick a large pot that provides decent drainage. Choosing a container for a potted delphinium will take some thought. First, make sure whatever pot you choose, it has drainage. Delphiniums do not like sitting in water. They like to be evenly moist and never dry, but sitting in water will cause them to turn yellow and die.