Most likely, you first saw the tall and stately spikes of Larkspur flowers growing in your grandparent’s flower garden. When in bloom, these big flower spikes are lovely in the garden and indoors in vases. They are members of the Delphinium family. There are many varieties, and it should not surprise you that they range in height from one to seven feet. When growing larkspur plants, place taller varieties at the back of the flowerbed.
Best of all, tall-growing Larkspur plants produce flowers that burst into bloom when many other flowers are still weeks away.
Did you Know? Larkspurs can be poisonous to some animals, most notably cattle. However, home gardens usually do not have cattle grazing in the flower beds.
Flowers Bloom: Spring, Summer, or Fall, depending upon variety.
Flower Colors: Colors include light and dark pink, blue, rose, lavender, and white.
Plant Height: 3′ – 5′
Annual, Consolida Orientalis
The plants are started from seed. Directly sow Larkspur seeds into your flower garden after all danger of frost.
Sow Larkspur seeds early in the season and cover lightly with 1/8″ of garden soil.
Space the plants 4 inches apart. The final spacing should be 10-12 inches apart.
Larkspurs are Rhizomes. You can separate the rhizomes of established plants and replant them in new areas.
Days to Germination: 10 – 15 days.
Larkspur plants grow their best in full sun to partial shade. They are very easy to grow and grow rapidly.
The plants do well in average soils and cool weather. Yet, we still recommend mixing in an ample amount of compost at the planting site.
The soil needs to be kept moist to feed their quick growth. Water them during dry periods, once or twice per week.
Add a general-purpose fertilizer once a month until after they have bloomed.
Cut blooms just before they peak. Place them in a vase and arrange with other flowers, or alone by themselves.
Once your Larkspur plants are established, they will grow well until the first frost. The plants are annuals and highly susceptible to frost.
Ideal Soil pH: 5.5 – 7.0.
Fungal disease is common, most notably Sclerotium rot which yellows leaves and wilts plants. Larkspur is also affected by mildew. Treat affected plants immediately with a general-purpose fungicide. Remove seriously diseased plants to keep the disease from spreading.
Insect problems are less frequent. Organic or chemical insect repellents are effective against most pests.
Plant Problems – Find the causes and cures.