The Beginner’s Guide to Fall Bulb Planting
If you want beautiful blooming spring bulbs, fall is the time to plant them. Join gardening expert Melissa Strauss for a beginner's guide to fall bulb planting for your own beautiful spring garden.
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Planting bulbs in the fall is the best way to have a vibrant garden full of flowers in the spring. The reason for this is that fall planting aligns best with the natural growth cycle of these plants. The planting conditions are ideal this time of year, and give your bulbs what they need to perform at their best in the spring.
Fall planting gives bulbs the cool temperatures combined with warm soil that best encourages root development. By planting in the fall, your bulbs will set down a solid root structure. But they won’t grow green growth until after they are exposed to much colder temperatures.
When you plant in the fall, your bulbs will root sufficiently and then go dormant during the winter. This period of cold dormancy is essential for many of them to trigger blooming. By the time spring rolls around, they have established roots and are ready to send up strong green growth.
Bulbs planted in the spring miss out on the cold-conditioning period they need. The result is that many will perform poorly, and some will not flower at all. When you plant in the fall, you follow the natural cycle that they evolved with. This gives them the best chance to thrive.
Planting your bulbs in the fall takes a bit of work now. But I assure you, the reward will be an earlier and more successful display in the spring. Let’s talk about how to get those bulbs established in the ground for a gorgeous garden in the spring. Here is your complete fall bulb beginner guide.
Time it Correctly
The most crucial factor in this fall bulb beginner guide is timing. Technically, autumn falls between two specific dates, the autumnal equinox and the winter solstice. However, when it comes to planting times across climates, there is nuance to the question of ideal planting time.
What we consider to be fall weather here in zone 9 is quite different from what zone 4 gardeners would indicate. So to say that you should plant your bulbs in the fall is not quite specific enough. Instead, we need to look at our first frost dates and also consider when the ground will freeze.
One of the main purposes of planting bulbs in the fall is for their root development. The soil is still warm from summer, but the air is cooling. This encourages root growth, without sprouting, as the foliage would simply die off over the winter.
When the ground freezes, your bulbs will enter dormancy, so they will no longer continue root development. For this reason, you should time your planting so that the roots have ample time to establish before they go into dormancy.
Wait until nighttime temperatures are consistently below 60°F (16°C). Time your planting so that your bulbs have six to eight weeks to set down solid roots. In zones 3-5, late September to early October is a good time. In zones 6-7, aim for some time in October. In zones 8-10, you can begin any time between November and December.
Choose the Right Location
Choosing the right location is second on the list of important things a fall bulb beginner should know. The type of bulb you’re planting is relevant here, but for the most part, these plants need at least partial sun exposure. Full sun will lead to stronger stems and more vibrant, larger blooms.
Depending on your climate, the time of day that your space is in the sun is important. These plants don’t like warm temperatures. As soon as the weather begins to heat up, many of them will begin to fade. Some are more tolerant of heat than others, but in general, they need cool weather to remain vibrant.
Look for a spot that gets six or more hours of sun in the early part of the day. Morning sun is as effective as afternoon exposure, but it’s cooler. In warmer climates, look for a spot that gets sun in the morning and shade in the afternoon.
Choose Your Bulbs
If you’re a beginner, reading this fall bulb guide before you’ve decided on which flowers you want to grow is great! If you’ve already selected your bulbs, hopefully they are all appropriate for your climate. This is most commonly an issue in warmer regions.
Some bulbs need more cold exposure than others, so they won’t grow as well in warm regions where the soil doesn’t freeze. Tulips and crocuses, for example, need more cold than I get here in zone 9. I’ve tried planting them anyway, but they don’t perform nearly as well as my daffodils.
Here is a list of common bulbs and where they grow best. Some varieties are more or less tolerant of heat and cold. If you’re located just to either side of the indicated zones, look into finding varieties that are more tolerant.
- Tulips (3-7)
- Crocus (3-8)
- Hyacinths (3-7)
- Daffodils (3-9)
- Alliums (4-9)
- Snowdrops (3-8)
- Spanish Bluebells (7-10)
- Paperwhites (8-11)
- Anemones (7-10)
- Ranunculus (8-10)
For warmer climates, you can chill your bulbs in the refrigerator over the winter. Then, plant in spring if you want to grow the bulbs that require more cold exposure.
Prepare The Soil
Every beginner should know how to properly prepare the soil for planting bulbs. Fall-planted bulbs prefer loose, well-draining soil. Bulbs are prone to rotting if they sit in too much moisture. If you have compacted soil, or it remains wet all the time, your bulbs will rot, and you’ll end up with a sad result.
Clear your space of weeds, rocks, and debris, and loosen the soil down about 8-12 inches. Mix in organic matter like compost, manure, or leaf mold to improve texture and fertility. If you have sandy soil, you want to enrich it and make it hold more moisture. If you have clay soil, you want to loosen it up and improve the drainage.
Most bulbs prefer acidic soil, so a soil test in the fall is a great idea. While organic material will lower the pH slightly, you may need to make other amendments. After you prepare your soil, rake it smooth before you set about planting.
Depth and Spacing
Now for the fun part. Once you’ve selected the location and prepared your beds, it’s time to get planting. The depth and planting of your fall bulbs is integral to proper root development. Planting your bulbs too shallow can cause them to heave out of the soil when it freezes and thaws.
A good rule to follow is to plant your bulbs at two to three times their height. For example, a large bulb, like a tulip, is about two inches tall. Plant these four to six inches deep. Some larger plants, like alluims, will need to go even deeper. Smaller bulbs like crocuses can be shallower, at three to four inches deep.
Spacing is another important factor for the beginner. Your fall-planted bulbs need space to breathe and grow roots. They will also create offsets over time. These need space to form, and if you plant too close together, you’ll end up having to divide them sooner.
For large bulbs, leave about four to six inches between. You can plant smaller ones closer together. Two to three inches is typically fine for crocuses.
If you want an orderly, organized bed, planting in straight rows is fine. Many gardeners prefer a more natural look. Planting in drifts or clusters will better achieve this look. Odd numbers tend to lend an overall more natural appearance.
Position Your Bulbs Correctly
Positioning your fall-planted bulbs correctly is an important factor in success. Even with seeds, placing them with the correct end facing in the correct direction is important.
Bulbs grow roots from the flat part, and shoots from the pointed end. Make sure that you plant them with the flat end facing downward and the pointed end facing up.
Cover and Water
Once your bulbs are in place, cover them loosely. Backfill over the holes, but don’t compact the soil. Allow it to remain loose and have proper drainage. Water them thoroughly and deeply to ensure good contact between the bulb and the soil, and to eliminate air pockets.
After the initial watering, keep the soil just evenly moist. Don’t allow it to get soggy. If you get regular rain, you won’t need any additional water. Fall tends to be a rainy time of year in many locations.
If you’re experiencing a dry fall, check the soil once a week and water lightly when it is dry. Once the ground freezes, you should stop watering as the bulbs are dormant. While dormant, they cannot absorb or utilize the water, and it can result in rot.
Mulch
Mulching over your fall-planted bulbs is a smart move that will provide several benefits. A two to three-inch layer of organic mulch helps to insulate the soil. It moderates temperature shifts and reduces stress.
Bulbs that are planted too shallow can heave out of the ground during its freezing and thawing process. Mulch helps to prevent this, as well as conserving moisture and suppressing weeds in the spring.
