After learning more about chilling, you probably want to learn how to cool flowering bulbs. Tulips and narcissus need a 12- to 16-week cooling period before they blossom in the spring. The recommended temperature for chilling bulbs in a refrigerator is around 40 degrees Fahrenheit (4 degrees Celsius). Just be careful not to store them close to any fruit, as the ethylene gas released will lessen bloom. The bulbs should be kept in a vented mesh bag in the refrigerator.
The length of the cold period for bulbs varies depending on the species, but generally speaking, the flowers that emerge earliest, even through snow, require the least amount of chilling time, while those that do so later require the most.
Does planting daffodils require chilling them first?
The majority of spring-blooming bulbs, such as tulips, daffodils, and crocuses, are native to regions with harsh winters. In order for these bulbs to blossom successfully, you will need to “pre-chill” them if you live somewhere with moderate winters and little frosts (zones 8–11). The steps are listed below.
Warmer climate-adapted bulbs don’t need to be chilled first. These include Scilla peruviana, Freesia, Ranunculus, Anemone DeCaen, and Anemone St. Brigid. These winter-hardy bulbs can easily be planted in the fall for spring blossoms where they are located (zones 8–10).
The majority of bulbs that bloom in spring benefit from 10 to 14 weeks of freezing at 35 to 45F. These freezing temperatures cause a biochemical reaction in bulbs that “activates bloom production and starts root growth.” The bulbs will attempt to bloom without a cooling phase, but the flowers may be tiny and distorted. Bulbs can be pre-chilled for a longer period of time than advised, but not for any shorter period.
Start chilling the bulbs in mid- to late-October for best results, then plant them outside as soon as the chilling phase is over. As a result, the bulbs have more time to grow roots before concentrating on flowering. The bulbs will be prepared for planting in January or February if the chilling cycle is started in late fall.
As long as you don’t keep any fruit in the refrigerator while the bulbs are chilling, chilling your bulbs there is a simple choice. Ethylene gas released by ripening fruit will harm the developing blooms inside the bulbs. If you do decide to keep the bulbs in the fridge, make sure to put them in ventilated plastic bags to prevent drying out while they’re cooling.
Remove the bulbs from the refrigerator and plant them right away after they have chilled for the necessary period of time (see below). Select a planting place that will be shielded from the afternoon sun to prolong the bloom period. To assist retain moisture and keep the soil cool, you can cover the soil with a few inches of mulch after planting the bulbs.
The majority of pre-chilled bulbs will blossom 4 to 6 weeks after planting. Always treat pre-chilled bulbs like annuals.
Spring-blooming bulbs that should be pre-chilled at 35-45F
- 15 weeks Glory-of-the-Snow (Chionodoxa)
- 15 weeks for crocuses
- 12–15 weeks for hyacinths
- Muscari grape hyacinth: 12–15 weeks
- 16 weeks for daffodils
- 12–15 weeks for the Siberian squill (Scilla siberica).
- 10 to 14 weeks for tulips
- Galanthus (snowdrops): 12–15 weeks
- 13–15 weeks for iris reticulata
Do daffodil bulbs go in the refrigerator?
Reader Trudy Stern sent me this query:
“Should I force my daffodils indoors in January or February, or should I keep them in the deep frost for a while? Tulips? Any unique advice? I am excited to enjoy some bulb beauty all winter long in my home.
I got in touch with Jeff Thompson, the horticulture director at the Buffalo and Erie County Botanical Gardens, because I believed this was a query that many readers could be interested in.
Before tulips, daffodils, and other spring bulbs bloom outdoors in Western New York, the Botanical Gardens puts on a grandiose Spring Flower Show each year. They know what they’re doing because they’ve forced hundreds of bulbs to blossom indoors for the display.
Although the bulbs require a chilly period, Thompson warned against freezing them. Place them in the fridge, not the freezer.
Put the bulbs in a top-opening opaque plastic bag, then place the bag in the crisper drawer. That will prevent your bulbs from drying out and shield them from the light that comes in through the door every time you open it.
You must have an opening in the bag so that air may circulate. According to Thompson, if the bulbs become wet, mildew and fungi may develop and cause the bulbs to die.
According to David Clark, a botanist and national garden speaker, a paper bag will also work when storing bulbs in the refrigerator this fall. However, if you have apples in your refrigerator, be careful not to store bulbs there. Ethylene gas, which is released by apples, can destroy the developing flower inside the bulb. View additional advice on how to plant spring bulbs in your garden here.
Plant the bulbs in pots, give them water, and then put the pots back in the refrigerator after the bulbs have been in there for a few weeks. While they are chilled, don’t water them once more.
“You’re attempting to deceive people into thinking they’ve experienced winter, Thompson said.
Remove the pots from the refrigerator, place them somewhere warm, provide them with light, and water them three to four weeks before you want the plants to grow and blossom.
Since November 25 some bulbs have been potted up and kept in the cooler by the Botanical Gardens personnel in anticipation of the March Spring Flower Show. The question’s author is hoping for them to blossom in January or February. You might be able to reduce your simulated winter and still obtain effects, Thompson added, if you haven’t already started chilling your bulbs.
Thompson mentioned that you might be able to find potted narcissus, hyacinths, and paperwhites right now. You don’t need to refrigerate those because the farmers have already chilled them.
How are daffodil bulbs pre-chilled?
In regions where the soil temperature doesn’t sufficiently cool during the winter, often USDA Zones 8, 9, and 10, spring-blooming bulbs need to be pre-cooled, or pre-chilled. Here, pre-cooling is necessary for crocuses, tulips, and hyacinths. Place bulbs in the refrigerator’s fruit and vegetable drawer for 8 to 14 weeks to pre-cool them. However, avoid storing them near ripening fruit as this can release ethylene gas, which can harm the bulbs. The bulbs should then be planted right away in the garden or in pots.
In areas with mild winters, consider bulbs that don’t require pre-cooling to avoid having to do it. These include, among others, daffodils, narcissus, iris, freesia, scilla, and triteleia. A reputable bulb catalog will specify which options need for pre-cooling and which are suitable for warm winters. Numerous bulb suppliers also provide pre-cooled bulbs; they will preserve your purchase in a cold storage facility and send it to you when planting time arrives (December or January in warm areas).
Check out our two illustrative how-to files, Gardening with Bulbs & Tubers and Bulbs.
When should bulbs be placed in the refrigerator?
According to the Clemson University website, tulip bulbs must be forced out of dormancy by being refrigerated for 12 weeks at or below 40 degrees Fahrenheit in order for them to bloom. Three months after you first place them in cold storage, take them out of the fridge. Put the tulip bulbs in the fridge by the end of October, and take them out in late January, for instance, if you want the flowers to blossom in February.
Although the bulbs must be kept cold, cold storage by itself won’t cause the tulips to bloom. After the cold treatment, pot them properly and give the right cultural conditions for them.
Which month is ideal for planting daffodil bulbs?
- After plants stop blooming, let daffodil leaves naturally fade back.
- If daffodils get too crowded and cease flowering, divide them.
Without daffodils, no spring garden is complete. Furthermore, they are frequently the only plants blooming in the garden in the early spring, so you really can’t have too many of them. Since daffodils are perennial plants, they return year after year and are among the easiest spring flowering bulbs to raise.
How to Choose Daffodils
The majority of daffodil cultivars grow best in milder climates because they need a period of cold weather each winter to encourage blooms for the following spring (zones 7 and lower). However, there are some types that thrive in warmer climates (zones 8 and higher), and bulb catalogs will always include them. There are numerous daffodil types available.
Daffodils come in all sizes, including some with enormous blossoms. Bulbs with peach, orange, yellow, pink, white, or bicolor flowers are available to purchase. There are season-specific early, mid, and late bloomers. You may enjoy three months of daffodil blossoms with careful planning! Even 100-day mixtures of bulbs are available in some stores, making it simple for you to take advantage of an extended daffodil season.
Where to Plant Daffodils
Daffodils should be planted in a sunny area that receives at least 6 hours of direct sunlight each day. The plants won’t blossom if they are planted in partial shade, but they will still produce green leaves. Daffodils, like the majority of bulbs, demand well-drained soil; otherwise, they are susceptible to rotting.
When to Plant Daffodils
Fall is the ideal season to plant daffodil bulbs (exact timing can range anywhere from September to late November, depending on where you live). When you plant, the earth must still be usable but the soil must have cooled. Daffodil planting requires soil that is 60 degrees Fahrenheit and 6 inches deep.
How to Prepare the Soil for Planting Daffodils
Mix 3 inches of Miracle-Gro Garden Soil for Flowers into the top 6 to 8 inches of the existing soil to prepare new planting sites. As a result, bulbs will receive the nutrition they require to develop a sturdy root system in time for spring blossoming.
How to Plant Daffodils
Daffodils can be planted singly, in groups (3 or 5 is a good number), or in rows. It is simpler to dig a trench or a large planting hole if you are planting many bulbs in a row along the edge of a flowerbed. You should plant them individually if you’re randomly putting them in a flowerbed or on the grass. The spacing between bulbs, regardless of how many you plant, should be 4 to 6 inches.
Each daffodil bulb should be planted with its pointed end (or tip) facing upward. When the bulb is inserted, dig the hole or trench so that the tip is 2 inches deeper than the bulb’s height. Therefore, a 2-inch long bulb should be planted 4 inches deep, while a 3-inch long bulb should be planted 5 inches deep (measured from the bottom of the bulb). After planting, give the soil plenty of water, and then add a layer of mulch to keep the area looking neat and to help the soil hold moisture longer.
How to Water Daffodils
Daffodils should be well watered at planting time and then once per week throughout the following three weeks. (Watering is essential at this period since the plants are developing their first roots.) After the first few weeks, don’t disturb the plants again until the spring, when they’ll start to grow.
When you notice daffodil leaves poking through the ground, it’s time to focus once again. While daffodils are growing and blooming, water the plants if your area doesn’t get any rain for two or three weeks. Spring storms typically supply enough of moisture. Once the blossoms have faded and the foliage starts to turn brown, stop watering because this signals the start of a time of dormancy and too much water might cause the bulbs to rot.
How to Feed Daffodils
A powerful combination of excellent soil and the ideal plant nourishment produces stunning garden outcomes. So, to aid the bulbs in storing nutrients for the following growing season, feed daffodils with Miracle-Gro Shake ‘n Feed Rose & Bloom Plant Food after they have blossomed in the spring. Feed as directed on the label every three months, and once the foliage turns brown, cease feeding.
What to Do with Daffodils After They Bloom
Daffodil plants will be prompted to focus energy back into the bulb rather than setting seed if wasted blooms are removed after blooming. (This method is known as deadheading.) After the plant has finished blooming, keep the leaves upright and unfolded so that the plants can use photosynthesis to produce and store food for the next spring’s blossoms. Before you do any trimming back, let the leaves naturally die down. If you want to create a screen around the daffodils if you don’t like how the foliage is beginning to turn brown, consider planting late-emerging perennials.
How to Divide Daffodils
Daffodils need to be divided in the fall if they are in full sun, have been allowed to naturally die back the previous spring, and are not flowering when they need to. Each spring clump that needs to be divided should have a golf tee placed next to it so that when they die back, you can easily locate them. Break separate the bulbs in each clump and excavate it. The biggest bulbs should be replanted at least two bulb widths apart. (When dividing, little bulbs might remain affixed to larger bulbs.) As if you were planting new bulbs, prepare the soil.
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