Ask a Master Gardener
Planting Bulbs
10/8/24
I’m not sure why I like planting bulbs so much. Maybe there are several reasons. Such as, planting bulbs isn’t difficult, and there is a special bulb planting tool that makes it very easy. All you need to do is push it down into the soil, lift it out, drop in a bulb, replace the soil. Plus, bulbs give you a little surprise to look forward to in the spring. Oftentimes after you forgot planting bulbs, you have a pleasant surprise in the spring when you see those green leaves start to poke up out of the soil.
It’s still a little early to plant bulbs. We want the soil temperature to be in the 50s when planting and right now 2-to-4-inch soil temperatures are in the mid to upper 60s. To find out your soil temperature you can purchase an inexpensive soil temperature thermometer, or you can just visit mesonet.org. The Mesonet is a joint project between OU and OSU to provide weather data throughout the state. I know when I want to check how much rain we received at our Seed to Supper Farm, I just look at the Mesonet since there is a data collection site at the OSU Research Station where our farm is located. But rainfall amounts are just some of the info available on the Mesonet. As a gardener, you should make yourselves familiar with our Mesonet.
While it’s too early to plant, it’s not too early to shop and one thing about shopping for bulbs, the early bird definitely gets the better selection, be that online or in your favorite garden center.
When shopping for bulbs, yes, the first thing that pulls us in is the bloom, but there are a variety of ways to select which bulbs you are going to plant. My first suggestion is to consider bloom time. With bulbs, we have the early bloomers like hyacinth, crocus, and some early tulips. Next come the mid-bloomers like tulips and daffodils which are followed by the later bloomers like iris, allium, bluebells, and the remaining tulips. Why consider bloom times? Since the flowers on bulbs are so short lived, you can extend the season by planting bulbs that will bloom on a somewhat staggered basis.
Once you get your bulbs, you’ll need to decide where you are going to plant them. Now some gardeners say you should figure out where, before purchasing your bulbs, but who are those people? As gardeners, we all know that we buy first, and figure out where to plant later…right? No? Ok fine. It’s just me.
Bulbs are going to do best in well-drained soil because, as you can imagine, bulbs sitting in wet soil tend to rot. If your desired planting spot is high in clay, you’ll want to amend with some organic matter like compost or composted manure. Sun and shade don’t usually matter since bulbs tend to bloom before the trees leaf out in the spring.
Phosphorus is an important soil nutrient for bulbs and to know your phosphorus levels, you’ll need to get your soil tested. If that isn’t going to happen, plan on working a little bonemeal into your soil before planting since bonemeal is about 12% phosphorus. Then in the spring when you start to see the leaves, give them a little boost of 10-10-10. But don’t fertilize after they begin to bloom.
When planting, bulb size determines how deep you are going to plant your bulbs. The general rule is to plant them about two to three times the vertical size of the bulb deep. So a bulb that is about an inch tall should be planted 2 to 3 inches below the soil level. And be sure to place them in the hole, large size down.
If you have a problem with gophers, you should consider a preventive strategy when planting bulbs. In this case you can dig a shallow trench, line the bottom with chicken wire, place the bulbs on the chicken wire, cover them up with a little soil and then place chicken wire on top, and continue to cover with soil. This will at least make the gophers work a little for their snack, but hopefully it will be enough to discourage them.
After you get them planted, water them in and cover with mulch. Except, if you are planting some of the early bloomers, don’t cover them with mulch, since mulch could keep the soil temps cooler in the spring and delay blooming.
After your bulbs have bloomed, don’t be in a hurry to cut down the green leaves since these leaves are gathering energy to store for next year’s flowers.
Some people like to dig out their bulbs and save them for next year, I am not one of those people. I just leave them in the ground and look forward to seeing them again next year. Whatever your approach, planting bulbs is one of the easiest things you can do in your landscape. And they are beautiful. See you in the garden!
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: Tom Ingram