Two Thumb Rules for Planting Flower Bulbs
There are two main questions starting to come up right now about planting flower bulbs and here are two rules of thumb to deal with them.
The first question is how deep do I plant bulbs?
The short answer (and there are a lot of longer ones) is that if it is a tulip bulb (or roughly the same size) plant it so the base of the bulb is 5-inches deep.
If it is smaller than a tulip bulb, plant it so the base of the flower bulb is 2-inches deep
If it is bigger than a tulip bulb, plant it so the base of the flower bulb is 8-inches deep.
Biggest rule of thumb. Planting flower bulbs isn’t rocket science. An inch here or there isn’t cause for plant failure and falling out of orbit.
The second question is “When Do I Plant My Flower Bulbs?”
You want to plant bulbs 6-8 weeks before the ground freezes in your area. Do not plant them when they come on sale (they’re on sale now around here).
This rule of green thumb means that in USDA zone 4, you’d be planting in early to mid October on an average year. For every zone warmer, you can plant the bulbs a week later.
This gives them enough time to set roots before the ground freezes but not enough time to start throwing shoots.
If you plant too early, the bulbs will not only set roots but will likely start growing underground shoots which will be frozen off and the bulbs will die over the winter. This is one reason we get so many “my bulbs died over the winter” type of complaints in the spring.
If you want more detailed information on caring for flower bulbs, you'll find it here.