Planting & Care of Bulbs: Fertilization and Mulching
While each plant is a complete “plant factory” in itself, with built-in nourishment, it is a good idea to mix a quantity of balanced fertilizer, compost, or leafmold with the loose soil at the bottom of your planting. This will provide additional food without any danger of “burning.” Never apply fresh or half-rotted manure directly on bulbs and perennials.
As soon as the shoots break through the ground in the spring, repeat the fertilizer application. Do not fertilize spring flowering bulbs after they have started flowering. This tends to encourage the development of bulb rot and sometimes shortens the life of the flowers. Summer and fall flowering bulbs should be fertilized monthly from shoot emergence until the plants reach full flower.
A year-round mulch of compost, leafmold, leaves or commercial types of mulch has a positive effect on your bulbs and other flowers by keeping the soil from drying out, maintaining a more even soil temperature and reducing weed growth. It also prevents soil from splashing onto the flowers and foliage
The optimum pH range for bulbs is 6 to 7. A soil test of the planting area is necessary to determine if lime needs to be applied to adjust the soil pH. If needed, limestone should be worked into the soil.