The best time to plant bulbs is September through October
When the leaves on the trees start to change color and drop to the ground, it’s a sign that fall is here. It’s also a sign that it’s time to plant bulbs so you can have a bountiful splash of color to mark the start of spring.
The best time to plant bulbs is September through October because the bulbs – especially daffodils -- need time to root well before the ground freezes. During the summer, bulbs are in a dormant stage because the weather is warm. They need low temperatures to break them out of their dormancy and start growing, according to Ohio State University Extension.
If possible, buy your bulbs as early in the fall as possible because that’s when there will be more of a selection. Look for bulbs that are dry and hard and try to buy the largest ones. The larger the bulb, the larger the flower. When deciding where to plant your bulbs, make sure there will be adequate sunlight in the spring. Bulbs can be planted under deciduous trees, which will provide only partial shade in the spring. Be aware that planting bulbs in a southern location next to a foundation could induce the bulbs to emerge too early, resulting in freezing injury.
When planting your bulbs, follow the guide on the planting chart. The rule of thumb is a depth four times the height of the bulb between the soil surface and the tip of the bulb,. For example, hyacinths should be six inches or deeper and daffodils, six to eight inches deep. Large bulbs six inches apart and two inches apart for smaller bulbs.
To grow the best looking plants, add a complete fertilizer such as 5-10-10 to the soil at a rate of three pounds per 100 square feet. Loosen the soil under the bulb and make sure there is plenty of drainage so the bulbs won’t be sitting in water. If the soil is a heavy clay, mix it with one-third to one-half organic material such as peat moss or compost.
Plant the bulbs with the growing tip up, or the pointy end up, think of a triangle when planting bulbs. For a greater effect, plant in clumps or irregular masses rather than singly.
Once planted, replace half the depth of soil, then water. Finish covering with soil and water again. If fall weather is dry, water as needed to promote good root development. Mulch may be placed over newly planted areas once the soil has frozen to a depth of one to two inches. This keeps soil frozen and prevents alternate freezing and thawing, which may cause the soil to heave and injure newly planted bulbs.
Mulch can be placed over bulbs planted very late in the season to extend the root development period. The mulch can also be used to keep prepared soil from freezing. This method can be used for bulbs, such as hardy lilies, that cannot be obtained until very late in the season. After planting and as soon as soil has frozen to a depth of one to two inches, replace mulch.
Some bulbs are bothered by rodents, particularly squirrels, chipmunks, and mice. They dig and feed on (or store) tulip, Crocus and Lily. Daffodils and hyacinths are not bothered. If rodents are a problem, and only a few bulbs are to be planted, consider enclosing them in hardware cloth boxes (use 1/2 inch mesh), or lay a sheet of hardware cloth over the planted area before replacing soil. Bulbs may also be dipped in Ropel®, a taste repellent, before planting to repel rodents. In spring, rabbits feed on tulip and lily foliage. Chicken-wire enclosures or some of the taste repellents work fairly well.
For more information about selecting and planting bulbs, visit: http://ohioline.osu.edu/hyg-fact/1000/1237.html