When fall comes around, and spring-flowering bulbs are ready to make their way into the ground, hands down one of the most commonly asked questions for new bulb gardeners is “how deep do I plant?” And with a quick Google search yielding a whopping 30 million answers in seconds, we can’t blame them for being a little confused. Thankfully, though, the answer isn’t nearly as complicated as it may seem.
How Deep to Plant Bulbs
When planting bulbs, the trick is to plant them not so deeply that it takes them too long to appear in spring, but also just deep enough that they don’t pop up too soon and waste away in the wintery weather. So, the general rule of thumb is to plant them at a depth of 3x their height. That means that if a bulb is around 2 inches tall, you’d plant them at a depth of 6 inches. Dig out your hole—or trench, if you’re planting multiple—and pop them in pointy end up for a spectacular show!
Now, this rule is assuming that your soil conditions are ideal and well-draining. However, if you’re working with other soil types, you may need to plant a little deeper or shallower. In sandier soils, or soils that don’t retain water as well, bulbs should be planted a little deeper than usual to ensure they get the water benefits for as long as possible. In clay soils, where the water retains even more than usual, they should be planted a little less deeply, so they don’t stay waterlogged. Of course, the best way to avoid confusion with planting depths is simply to amend your soil before planting to give your bulbs the ideal conditions to grow in!
How Deep Do You Plant Tulips?
Now, here’s where a lot of the confusion comes from. Tulips are one of those bulbs that seem to cause quite a headache when it comes to planting depths. This is because, for many years, gardeners were told over and over again that tulips preferred deeper planting than most bulbs—8 inches being the golden standard. But a recent study at Cornell University actually debunked that myth, proving that tulips can bloom just as beautifully when planted less deeply. In fact, they actually tested bulbs planted right on top of the soil with only a layer of mulch on top, and they did just fine!
The trouble is, though, that pesky pests, like squirrels and rodents, enjoy the taste of tulip bulbs, and are all too happy to get their paws dirty digging them up for a cool-season treat. So, to give our new plantings a chance, we recommend planting them at a depth of at least 6 inches. We also recommend planting them with a few pest-resistant bulbs nearby to dissuade any discerning taste buds.
Planting Depths for Spring-Flowering Favorites
Given the rule of planting at a depth of 3x the bulb’s height, you shouldn’t have too much trouble digging down and getting them in the ground just how they like it. But, to save you from a little mathematics, here are the typical planting depths for these popular spring-flowering favorites.
Daffodils offer some of the sunniest spring colors you can find in the garden, and they’re also ultra pest-resistant. Plant them at a depth of about 6 inches.
Lilies are fantastic, showy blooms that really make a statement in the spring landscape. Plant them at a depth of 6-8 inches, depending on the size of the bulb.
Irises have truly unique flowers that really pop anywhere they’re planted. Growing irises is actually much different from others on this list, mainly because they are grown from rhizomes, not bulbs, and should be planted just under the soil’s surface.
Hyacinths produce some of the prettiest plumes of vibrant flowers you can find in the garden. Plant them at a depth of about 6-8 inches. Grape hyacinths, also known as Muscari, however, should only be planted at a depth of about 3-4 inches.
Gladiolus are classic late spring blooms that are a fantastic choice for cut gardens. Plant their corms at a depth of about 4-6 inches, depending on the size.
While it may seem like a challenge to figure out planting depths when they vary so much from bulb to bulb, as long as you follow the rule of 3x the height, we can guarantee you’ll have success almost every time. But, if you’re still hesitant about how deep to plant bulbs in your garden, we’re here to help! For any questions—big or small—contact us today.
