Planting bulbs too deep can result in bulb rot and a bit of a delay in spring growth.
However if you plant bulbs too deeply, they may not flower—or they will flower too late.
To plant flower bulbs too shallow can expose them to damaging temperature spiking. Planting flower bulbs too close together can cause root systems to strangle each other or cause them to dehydrate or starve due to limited water and nutrition.
The general rule is that bulb planting depth should be between two to three times the length of the bulb. That means that a small bulb like a grape hyacinth will be planted closer to the surface of the soil than a large bulb like a tulip. If your bulb is an inch (2.5 cm) long, you will plant it about 3 inches (8 cm.)
Daffodil bulbs should be planted so that their pointed tops are about 4” - 7”, or about three times the size of the bulb, below the surface of the soil; allow 4 - 5 bulbs per square foot when planting outdoors.
Too-deep bulbs can suffocate and rot, and one sign of survivors is that they put out leaves but no blooms and typically have a very long, whitish stem between the bulb and the green above-ground leaves. You can also do this move in the fall if you mark the beds and know where the bulbs are.
Making sure you have the right amount for the space you are planning in helps ensure you get the right look! Generally, having too many bulbs isn't a big problem. You can always gift the extras to friends and neighbors. However, if you end up planting too few bulbs you may find yourself disappointed in spring.
The general rule of thumb for planting spring bulbs is to plant two to three times as deep as the bulbs is tall. This means most large bulbs like tulips or daffodils will be planted about 6 inches deep while smaller bulbs will be planted 3-4 inches deep.
Place the bulbs with the pointy-end up and with the roots down. If you're not sure of the top or bottom of the bulb, plant it on its side and it will find its way to the surface. Cover with soil and a light layer of mulch. Newly planted bulbs should be watered well to get settled in.
If you plant them too deep, the bulbs may not be able to grow and if they aren't planted deep enough they may begin growing too early. Packaged bulbs include instructions for depth but if you have bulbs without instructions the general rule of thumb is to plant bulbs 3 times deeper than the bulb is wide.
After planting, if it's dry, water well several times after you plant. Fall bulbs don't readily root in dry soil. In places where there's a dry autumn and then a hard freeze, the bulbs can die because there's not enough moisture in the roots.
For the best effect, we recommend planting daffodils in groups of five or more. Some gardeners, though, plant hundreds of daffodil bulbs to create a burst of color in the springtime. Daffodils contain a toxic liquid called lycorine in their bulb and stem, making them deer resistant.
There is no real reason to dig up tulips bulbs each year, or at all. Most gardeners leave their bulbs in the ground where they were originally planted, and, are left to rebloom. Sometimes gardeners will dig up tulip bulbs but only when the plants seem to have offered fewer flowers.
Answer: The problem with planting annuals over tulip bulbs is that tulips prefer to be kept totally dry over the summer. When you water the annuals, you increase the chance your tulip bulbs will rot.
Should you soak spring bulbs before planting? There's no need to soak them before planting. However, if you are late getting them into the ground, then soaking them for 12-24 hours can speed up the rooting process. Adding fish emulsion or liquid kelp to the water before soaking will help them root even faster.
Most bulbs can be stored for up to a year, but tend to perform best when planted within six months of lifting. For tender bulbs, be sure to plant in the spring following the fall in which they were lifted-they will likely not have enough energy to survive past the warm season and into the following year.
Bulbs grow best in well-drained soils and may rot if planted in soils that are too wet for an extended length of time. Hopefully the rainy weather will soon end and allow soils to dry a bit to permit planting. Plant bulbs in a location that is free of standing water and will receive six to eight hours of sun per day.
Plant Like a Pro
Plan on 9 to 12 bulbs per square foot. For a full look, put 2" to 3" of space between the bulbs. Using a 4" spacing will stretch the bulbs, but not look quite as full. To plant a lot of bulbs fast, dig out the entire planting area to a depth of 6 to 8” and pile the soil on a tarp nearby.
Three to six bulbs are suggested as a minimum number of summer bulbs of the same variety to plant in a grouping. Planting in Small Spaces - Plant bulbs of one colour in small spaces in the landscape. One colour will have greater impact and make the planting space look larger.
A “poke” approach to planting involves creating a small hole in the soil and dropping in one bulb, although planting two or more bulbs in one hole is okay for some smaller species of flowers. You can use any small garden trowel or garden knife (like a Hori-Hori) to dig the hole.
You can continue to store the bulbs in a cool location where the temperatures remain above freezing. Then plant the bulbs outdoors as soon as the soil is thawed and workable. If the plants received sufficient cold in storage, they will eventually flower for you this spring.
Sometimes bulbs can become overcrowded and this may cause them to flower less. Every few years or when you suspect this is happening, dig up and divide your clumps and replant them. This can be done in late summer or fall, after the foliage has died back.
Many bulbs readily multiply by producing offsets without any help from the gardener. But as well as taking advantage of this, it is quite simple to grow more of your favourite bulbs using just a few other techniques, including scaling, bulbils, seed and division.