How to Fertilize Flower Bulbs

Bulbs seem so self-sufficient, and come all ready to go. Just plant them, add water and in no time they produce glorious flowers. But flowering bulbs do have nutritional needs---many feed quite heavily, in fact---so the trick for gardeners is applying the right kinds of fertilizers at the right time. For one thing, a plant that grows from a bulb can only take in nutrition while its leaves are green and the plant is growing. For another, it's important to care for your bulbs properly in all ways to get season after season of beautiful blooms.

Bulb planter

Garden trowel

Commercial bulb food, or

Bone meal mixed with greensand and cottonseed or blood meal

Liquid fish fertilizer, or

All-purpose commercial fertilizer

Start bulbs off right by digging in some bone meal, blending it with the soil at the bottom of the planting hole. When roots begin to develop and the plant begins to grow, fertilizer will be there already to provide a boost. Bone meal is an ideal starter food, low in nitrogen but with lots of phosphorus and some potassium, and mild enough to avoid "burning" the bulb as it emerges from dormancy in spring.

Feed your bulbs again as they emerge in the spring. Slow-release bulb fertilizer is best. For daffodils the 5-10-20 or 10-10-20 formulation is recommended (the ratios represent nitrogen, phosphorous and potassium), and 9-9-6 is ideal for tulips, lilies and most other bulbs. All-purpose 5-10-10 fertilizer is fine too. Organic gardeners can use liquid fish fertilizer solution as an all-purpose food, and for slow-release fertilizer, use the combination of blood or cottonseed meal (nitrogen), greensand (potash or potassium) and bone meal (phosphorous).

Gather up unsightly plant stems after bulbs have bloomed using rubber bands or string, very loosely, if you need to neaten up the flowerbed. But don't cut them off while they're still green. Each bulb is busy reabsorbing plant nutrients from its stems as it slowly moves into dormancy---food energy for next year's growth is stored in the bulb---and removing those fading stems too soon will rob your bulbs of a healthy start next year.

Fertilize your established bulbs annually each fall, mixing bone meal or slow-release bulb food into the top 2 or 3 inches of soil.

Gladiolus bulbs will produce bigger flowers if you water each plant with liquid fertilizer solution (use as directed) for several weeks after flower buds form.

Fertilize garden lilies in spring just as shoots emerge, and again just before they bloom.

If you using organic, animal-based organic fertilizers---blood and bone meal or fish meal---be warned that dogs, skunks and raccoons may dig up your bulbs looking for food.