Dutch iris bulbs are planted in fall for blooms the following early summer. They ask for very little: decent drainage, sun, and a few inches of soil above them.
Planting
- Unbox right away. Open the package on arrival and store the bulbs in a cool, dry, dark spot until you can plant.
- Pick a sunny site. Choose a spot with full sun to partial shade and soil that drains after rain; iris tolerate most soil types but dislike standing water.
- Set the depth. Dig or drill holes 4 to 5 inches deep and place each bulb pointed end up.
- Space them close. Keep bulbs 3 to 4 inches apart, or cluster 8 to 10 together for a bolder color drift.
- Backfill and water in. Cover with soil, firm gently, and water once to settle the bed.
- Container option. Use a pot at least 8 inches deep with drainage holes and quality potting mix, then move the pot to a sheltered spot for winter.
Watering
- Fall and spring. Keep soil lightly moist while roots, foliage, and buds are developing.
- After bloom. Taper off watering as foliage yellows; dormant bulbs prefer drier soil.
Feeding
- At planting. Mix a balanced bulb fertilizer or bone meal into the planting hole.
- Each spring. Scatter a low-nitrogen granular fertilizer as shoots emerge to fuel next year's flowers.
Aftercare
- Deadhead spent blooms. Snip the flower stem once petals drop, but leave the foliage in place.
- Let leaves ripen. Allow the grass-like foliage to yellow naturally before removing it so the bulb can recharge.
- Mulch in cold zones. A 2-inch layer of mulch after the ground cools helps buffer winter temperature swings.