Every year some folks walk into the garden centre describing beautiful tulips in the neighbors flower bed and asks the same question: When is the best time for me to plant my bulbs? Spring flowering bulbs are one of the few garden purchases where the timing is reversed from what feels natural. Planting in the fall pays off in a big way five to six months later while missing the window can mean waiting the full year.
Why Fall Is the Right Time for Spring Bulbs
A tulip bulb sitting in a basement is waiting for a signal to start its growth and that signal is cold. Cold soil over the course of 12 to 16 weeks below 10°C is required before they’ll flower properly. This period triggers the bulbs internal chemistry and causes the stem to push up and bloom once the ground warms again. Bypassing this period results in weak growth or no flower at all. This is why most garden centres sell their bulbs in September as opposed to March. Root development should also be kept in mind as a bulb planted in October has weeks to grow out its roots before the soild freezes up. Come spring that plant can pour all its energy into flowering and growth given its already established root system.
The Ideal Planting Window for Kingston and the Surrounding Area
For homeowners in Kingston, Amherstview, Odessa, Loyalist Township, and out toward the Thousand Islands, the sweet spot for planting bulbs falls between mid-September and late October. You’re aiming for soil that’s cooled down from the region’s summer heat but hasn’t started to freeze. In this region that usually means daytime highs settling into the low teens Celsius, with the first hard frosts still a few weeks out. Plant too early, in warm August soil, and bulbs can send up premature growth that will get hit hard once the cold comes. Plant too late, after the ground has locked up solid, and you may not get a shovel in at all let alone experience any meaningful root growth. A helpful tip for the South Frontenac area is to wait until the maple trees have begun to really change colours to begin planting.
Timing by Bulb Type
Like all plants, every bulb is different and not every bulb is best suited for the same planting date.
Daffodils can come first and ideally are in the ground by mid to late September. These are the most hardy of the more common spring bulbs and will actually benefit from the extra bit of time to establish its roots before the winter months.
Crocuses or snowdrops follow a similar timeline to daffodils and prefer getting into the ground mid to late september.
Tulips are better suited to go in as late as early November in a more mild year. Many experienced gardeners prefer to wait to plant tulip bulbs until later to allow soil temperatues to drop further as tulips can be more prone to certain fungal issues in warmer or damp soil.
How Deep to Plant Flower Bulbs
Depth always matters when gardening but especially when it comes to planting blubs. As a good rule of theumb you’ll want to plant your bulbs about two to three tiems as deep as the bulb is tall. For most tuplips and daffodils this ends up being around 15 to 20 centimetres deep where smaller bulbs like crocsuses are genrally around 7 to centiemetres deep. Ensure you space your bulbs out about 10 to 15 centimetres so have space to grow throught the years and even consider staggering positions between bulbs that are being planted earlier vs later bulbs. Once planted make sure to water the area well to help settle the soil around the bulb and to work out any air pockets that may be present.
Getting your bulbs safely into the ground during the fall window means that next April’s garden colours will take care of itself. If you have any questions about which varieties suit your soil our garden centre team will be happy to assist. Stop by and we can help you pick the perfect bulbs for your garden rather than just grabbing whatever is on the shelf in October.
