Well-drained soil key for fall bulb planting
When do I plant fall bulbs? Do they need to be planted in the ground or can I put them in a plant container outside?
Now is the time to plant fall bulbs. Fall bulbs are those planted in the fall that bloom in the spring. These are things like daffodils, tulips, crocus, hyacinth and others. I’ll plant them anytime from the latter part of September through the month of October.
There’s a second group of bulbs I call spring bulbs, which are planted in the spring and bloom in the summer. These are things like dahlias, gladiolus and cannas. These are generally not winter-hardy here, so they need to be dug up in the fall and stored in a cool, dry spot over the winter for replanting the following spring.
The fall bulbs are perfectly winter hardy and will persist for years if planted and maintained properly. The most important thing they want is well-drained soil. That can be a bit of a trick in our heavy clays, but they really need a well-aerated soil to thrive. If the soil stays too wet, they’ll struggle and often rot into nothing.
This is why we so strongly recommend that people do a great job of amending the soil, especially below where the bulb will be planted so water drains down past the bulb. We usually recommend that you use a somewhat coarse, low-salt organic amendment like Soil Pep. Mix it half-and-half with your soil.
As I said before, be sure to mix it well below the bulb. If the bulb is going to be planted 5 inches underground, dig that 5 inches and then go another 12 inches below that to mix in the organic matter.
Be sure to water them in well after they’re planted. These bulbs actually do some important growing in the fall underground. If our fall is especially warm and dry, you may need to follow up with another watering in a couple of weeks. Put some mulch on top of the ground over the bulbs to help hold the water in and to moderate soil temperatures.
Growing bulbs in a pot is certainly possible, but there are a few tricks to it. The soil problem is often eliminated since you’re using a good potting soil in the pot that already has great drainage. The problem you can run into is with the winter cold. These bulbs are reliably winter- hardy in the soil, but above ground in a pot they will get much colder and can die off.
People try to get around this in a couple of ways. The first is to dig a hole in the garden and place the pot down in the hole and then bury it with some straw or sawdust. Having the pot surrounded by the soil will moderate the temperatures. Using straw or sawdust helps make digging the pot up easier in the spring while keeping the pot a bit cleaner.
The other option is to keep the pot in the garage or a shed. The tricky part about this is that the bulbs need to get cold. They need a certain number of hours of cold temps to set the trigger for the bulb to bloom properly in the spring. The garage may be a bit too warm for this to occur. The other problem is that it sometimes gets warm enough for the bulb to break dormancy and start to grow in the middle of winter. If that happens, you’ve got a problem because it’s extremely difficult to provide enough light for it to grow well. You need a spot that gets cold, but not too cold.