How to Thin Flower Bulbs in Summer

Bulb flowers such as daffodils benefit from dividing every 3-5 years. The time to divide is when the bed either appears overcrowded during spring blooming or there are fewer flowers than in previous years. The best times to thin the flower bulb bed is in mid- to late summer, when the plant begins to enter dormancy; there is less chance of damage to the bulb at this time. Use the bulbs removed during thinning to start new bulb beds or share them with other gardeners.

Difficulty: Easy

Instructions

Things You'll Need:

• Spade
• Compost
• Bulb fertilizer

1. Wait until after all blooms have faded and the foliage begins to die back naturally before thinning the bulb garden. Plan to dig up the bulbs 6 weeks after the final blooming period in spring.

2. Dig around the bulb, being careful not to hit it with the spade. Slide the spade under it and lift it from the soil.

3. Brush the dirt off the bulbs. Inspect them for signs of damage or soft spots that indicate rot. Discard any damaged bulbs.

4. Find the joint between two bulbs. Twist them apart while pulling gently. Discard any small bulbs as they will produce small or inferior flowers.

5. Lay a 3-inch layer of compost over the garden bed and work it into the soil to a 6-inch depth. Apply bulb fertilizer to the bed, following label instructions or using approximately 1 teaspoon per bulb.

6. Replant the bulbs in the bed, spacing large bulbs 6 inches apart and smaller varieties 3 inches apart. Use extra bulbs in a new bed, give them away or discard them.

Tips & Warnings

• You can also thin the bulbs in fall. Mark the location of the bulbs while they are blooming so you can find them in fall when there is no apparent foliage.
• Replanting immediately is best for most bulbs. If you must wait until fall, store them in a cool, dry place until ready to replant.
• Apply fertilizer around the planting area, not directly where the bulbs' roots will be. Fertilizer in direct contact with the bulb will damage them.

References

• University of Illinois Extension