Ask a Master Gardener

Fall Bulbs for Spring Color

10/13/20

Each spring I see the beautiful tulips and regret not planting them the previous fall. Any suggestion on how I should start gardening with bulbs? AR

I was late to the spring bulb party but now that I am in, it’s great fun. Now is the right time to start preparing and getting your bulbs.

Bulbs can be found at most of the local garden centers and the mail order houses still have a good supply. One thing that beginners with bulbs tend to overlook is bloom time. Different bulbs bloom at different times. There are early bloomers like crocus, hyacinth, and some tulips. There are mid-bloomers like daffodils and other tulips. And then there are the late spring bloomers link bluebells, tulips, iris, and allium. If you want to have a quick spring burst of flowers, you can stick with one variety. Or, if you would like a continuous coming and going of flowers, mix them up by bloom time.

Once you have made those difficult decisions, you need to get to work on the area of the flower bed where you plan on planting your bulbs. Well drained soil is important as wet soil can cause the bulbs to rot. If your soil has a high clay content, you can mix in some organic material such as compost or manure. Work this material in while loosening the soil to a depth of about 12 inches.

Phosphorus is a key element in the success of your bulbs so if you haven’t had a soil test and don’t know the phosphorus level of your soil, mix a little bonemeal into the soil before planting. Once you see growth break through the ground in the spring, sprinkle on a little 10-10-10. Do not fertilize after they have started flowering. Summer and fall flowering bulbs should be fertilized once a month until they flower.

If you haven’t already decided where you would like to plant your bulbs, that is next. Spring bulbs are pretty forgiving concerning shade since they tend to bloom before most trees leaf out. Summer bulbs will need a full sun location.

Now that you have your bulbs and your location is prepared, next comes planting. The key to planting bulbs (unless the instructions tell you differently) is to plant the bulbs two to three times as deep as the bulb is tall. This means bigger bulbs will be planted deeper that smaller bulbs. Bulbs also need to be planted with their nose up and the bulbous end down.

When planting, some people like to dig up the entire area, place the bulbs at the proper depth, and then cover them all up. For myself, I like to plant them individually. To plant them individually, you can use a garden trowel. However, bulb planting tools are relatively inexpensive and work pretty well. These tools can range in price from about $10 to $40. Or, if you like your power tools, you can get an auger attachment for your drill and be all fancy.

If you live in an area with gophers, you might want to take some additional precautions since gophers love tulip bulbs. If this is the case, you probably don’t want to plant your bulbs individually, but together in a trench. To discourage the gophers, you can line the bottom of your trench with chicken wire, place a little soil on top of the wire, place your bulbs, cover with some more soil, cover with more chicken wire, bury completely, and then hope for the best. Moles will not bother your bulbs as they eat worms.

Fall planted bulbs need to root before winter so water them in as soon as they are planted. You don’t want to overwater as this can encourage the bulb to rot, but also remember you planted these bulbs several inches below the surface so the water will need to reach that depth.

You should also mulch your bulb bed as it will help them avoid freezing in the winter and help moderate temperature and water fluctuation during the growing season. The exception to this is the small, early blooming bulbs like crocus or grape hyacinth which need no mulch.

One challenge some people experience with their bulbs is that after the bulb has bloomed in the spring and the bloom is gone, you will be left with the green foliage for a while. For me, I like it. It adds greenery to the garden, but for others, the party is over and they think it is time to clean up by removing the greenery. Don’t do that. The greenery is still at work storing energy for next years growth. For best results, you should leave the foliage until it turns yellow or dies back on it’s own. This process could take several weeks but just remember; the longer you leave it, the better your chances are for pretty flowers next year.

Once the foliage dies back the bulb is dormant until the fall rains wake them up again. The decision you then have to make is; do you dig up your bulbs or leave them. There are gardeners on both sides of the issue. As a general rule, some robust cultivars are fine being left in the ground while others are treated more like an annual by removal and then starting fresh the following year with new bulbs. I prefer to give them a chance and leave them to see what they will do. If they do well, great. If they don’t, time to do something else. Your bank account will also probably get a vote.

Either way, bulbs are great for new and experienced gardeners, so get some bulbs and get planting.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.

Photo: Leslie Ingram, Bugwood.org