The crocus is one of the garden’s first signs of spring, offering a welcome burst of color. While their bloom period is fleeting, post-flowering actions determine the success of next year’s display. Proper maintenance focuses on supporting the subterranean corm, the plant’s energy storage unit. Managing the energy cycle ensures the corm gathers enough nutrients to survive summer dormancy and guarantees a strong return the following spring.
Removing the Spent Flower Heads
Once the petals have faded, deadheading the spent bloom prevents the plant from expending energy on developing seeds. Interrupting the reproductive cycle redirects the plant’s resources back to the corm.
To deadhead, gently pinch or snip the withered flower head just beneath the bloom. It is crucial that the green stem and foliage are left completely untouched. The objective is to remove only the faded floral parts, keeping all green structures intact. This tidying step improves the appearance while benefiting the perennial health of the crocus.
Allowing the Foliage to Die Back Naturally
The most important directive for post-flowering care is to resist cutting back the remaining green leaves. This foliage acts as the plant’s temporary food factory for the next four to six weeks. The green leaves perform photosynthesis, converting sunlight into carbohydrates that are transported and stored in the underground corm.
Cutting the leaves while they are still green starves the corm, preventing it from accumulating necessary energy reserves. If removed too soon, the corm will be depleted and may fail to flower the next season or produce smaller, weaker blooms. Gardeners must wait until the leaves have completely yellowed and withered, indicating the corm has successfully pulled all remaining nutrients.
For crocuses planted in lawns, delay the first mowing until the foliage has turned brown and can be easily pulled away. In garden beds, fading leaves can be masked by planting low-growing groundcovers or allowing later-emerging perennial foliage to grow around them. This patience ensures the corm is fully charged for the dormant period and subsequent spring growth.
Ensuring Future Blooms Through Summer Care
Once the foliage has fully died back, the corm enters summer dormancy. Long-term maintenance shifts to preparing for the next year. While the leaves are still green, a light feeding of fertilizer can be beneficial. Applying a low-nitrogen, high-potassium bulb food or bone meal helps the corm store the right balance of nutrients.
Crocuses rarely require supplemental watering during the summer months. The corms prefer a relatively dry dormancy, as excessive moisture can lead to rot and fungal issues. Only during extreme and prolonged drought is light watering recommended to prevent the corms from desiccating.
Crocus corms naturally multiply over time, creating small offsets that cause the planting area to become overcrowded. After three to five years, a decline in the size and number of flowers signals that division is necessary to restore vigor.
The best time to lift and divide the corms is during summer dormancy, typically in late summer or early fall. Carefully dig up the clumps and separate the new, smaller cormlets from the parent corm. Replant these divided corms a few inches apart in fresh soil to ensure robust flowering the following spring.