(Last week it was 70 degrees, now it’s 20)
Let’s face it. It’s hard not to stress when your daffodils start popping up mid-winter. As weather becomes more unpredictable, early growth is becoming more and more common in spring bulbs. Not to worry, though. Your plants have seen it all before. Moreover, they’re built to handle a few temperature swings.
THE UNDERGROUND WORLD OF BULBS
To understand why spring bulbs can tolerate a little premature growth, it helps to take a peek underground.
Botanically speaking, a bulb is a short stem surrounded by fleshy leaves that store food during dormancy. As soon as you plant it in the fall, a spring bulb starts growing.
A bulb has five major parts: a basal plate, scale leaves, protective tunic, a flowering shoot and lateral buds. The action begins in the basal plate.
During the winter months, roots emerge from this modified stem to penetrate the soil. As they develop, the roots absorb water and other nutrients that they store in the scale leaves.
Photo credit/University of Illinois Extension
In some flower species like alliums, a thin papery covering called the tunic keeps the scales from damage or drying out.
Papery thin tunic keeps bulbs from drying out
In addition to providing food storage, the scales also protect the flowering shoot. This vital part of the bulb contains all of the future leaves and flowers. During the winter months, the shoot slowly grows upwards within the bulb, eventually developing into a stem.
Finally, at a pre-determined time in the spring, the leaves are the first to break through the soil. Then approximately one month later, the flowering shoot begins to appear.
At this stage in the process, the key thing to remember is this: the flowers develop independently of the leaves.
This means that even if your bulbs (specifically, leaves) come up early, the flowering shoots still need time (between 5 and 7 weeks) to develop. And before that happens, your bulbs have most likely weathered the warm spell and resumed dormancy.
So if you see leaves poking up out of the ground too early, don’t worry. A cold snap may cause them to yellow and die back, but the bulb will wait things out and send up new growth once temperatures warm up again.
WAYS TO STOP YOUR BULBS FROM COMING UP TOO EARLY
There are a few strategies, however, that you can implement now to slow things down while providing an extra layer of protection to the flowering shoot.
1. COVER YOUR PLANT
Covering the soil around your spring bulbs will help insulate them against extreme winter weather like frigid temperatures and drying winds. Try mulch, straw, bark chips, leaves or pine needles.
Or, if the plant is budding too early, try draping a cloth over it (securing it above the plant with stakes.) Remove the drape during the day so the foliage can absorb sunlight to warm back up.
2. WATER DURING DRY SPELLS
If there’s been a dry spell for an extended period of time, a little extra water during the day helps bulbs grow. However, make sure your soil has good drainage. Bulbs sometimes rot if they receive too much water.
3. IF FLOWERS START TO APPEAR
If the weather continues to stay unseasonably warm, your spring bulbs may start to produce flowers. Don’t worry. Even if frost kills off some of the initial buds, it usually won’t affect flowering in the coming months.
4. PLANT BULBS LATE IN THE FALL
The later in the fall you plant, the longer the bulb will take to sprout come spring. Wait until the temperature is cold enough (40°F or below at night) to plant your spring bulbs to ensure they are fully dormant. Here in Maryland, I plant my daffodils in late November.
Finally, make sure to plant your bulbs at three times their height in depth with the base down and the bud up. Planting bulbs too shallow leaves them vulnerable to frost heaves and can lead to premature growth.
For a list of ten popular spring bulbs and when and how to plant them, click here.
Author’s note January 2020: According to Science News, there is growing evidence that, in general, warmer springs are bringing earlier spring flowers. This in turn will result in longer growing seasons and drier summers. (This does not, however, mean daffodils in January.)