Why Bulbs Fail or Fail to Bloom - Solution Guide
Poor Drainage
- Most common garden bulbs cannot tolerate wet feet/roots. Soil must drain well for bulbs to do well. Unfortunately, in northern climates, excessive snow melting can lead to rotting bulbs. Assuming the bulbs were planted at the proper depth in the fall, if there is no growth in the spring, too much moisture or heavy soils with poor drainage are typically to blame. Only digging or excavating the bulbs will tell you for sure.
Lack of Proper Sunlight Leads to Weak or No Flowers
- Bulbs and bulb-like plants perform best when foliage gets plenty of sun. The foliage uses sunlight to convert energy into bulb mass. When bulbs do not get enough sun, bulb mass is weakened. Without enough mass, a bulb cannot produce flowers.
- Newly planted bulbs have the stored energy to bloom in the first season. In the second season, they may not bloom as well, depending on the care and nutrient replacement they received. This is why you leave the foliage on until it turns brown. When this happens, the bulbs have enough energy to bloom the following spring.
- The variety and cultivar can affect performance. Know what you're ordering and what to expect from those bulbs.
Planting Depth
- Bulbs that are planted too shallow often fail to bloom. Read & review instructions on individual bulb packaging for proper depth guidelines. As a rule of thumb, the bulbs should be planted 3 to 4 times the bulb's diameter. Deeper if you have sandier soil.
- Bulbs that get planted too shallow may freeze in severe winter temperatures or start to grow prematurely during winter.
- Bulbs planted too deeply often fail to bloom and can have weak growth that barely breaks the soil surface due to a lack of stored energy.
Pesky Rodents
- Hungry mice, voles, squirrels, or chipmunks can decimate an entire bulb bed over one winter.
- Do what you can initially to prevent predation, such as planting bulbs under wire mesh. Some repellents also help.
- Monitor for signs of rodent issues like digging or tunneling and take quick action.
Heat
- Never store your bulbs where they can become overheated, which can kill the embryo. Avoid places like a hot car trunk, a closed garage, a dresser drawer, a kitchen pantry, near the radiator, or even in a sun-filled room.
- Upon receipt, open all the bags to provide bulbs with proper air ventilation, but keep them in a cool, dark location until planting time.
Maturity
- Bulbs are only harvested for shipping after they have reached blooming maturity. They are conditioned to bloom the season after planting, but they must be provided with the proper conditions to do so.
- Some wild or native bulbs, often grown from seed, may need 1-2 growing seasons to reach flowering maturity. This is not a "defect"; it is just how nature works.
- Practice patience and have reasonable expectations since bulbs are growing plants that will change and mature given the time and optimum growing conditions.
Timing
- All bulbs are perennial plants; however, some varieties are better at naturalizing or perennializing than others.
- Some varieties perennialize well, but only in certain zones. Do your research or ask about a particular variety's capacities so you know what to expect.
- For perennial bulbs that produce large foliage, provide enough sun, nourishment, and proper watering to grow and flower properly. A bulb booster fertilizer helps if applied when the bulbs first emerge or right after they are done blooming.
- Some varieties grow foliage in the spring but flower in autumn. Conversely, some varieties produce their foliage only after they bloom. Before planting, familiarize yourself with the natural behaviors of the bulbs you chose.
- Some wild species may require a year or two to acclimate to garden conditions and their new location.
Over-fertilization
- Similar to other plants, bulb or tuber-forming plants that are over-fertilized, especially with nitrogen, may not bloom well. Use a fertilizer labeled "Bulb Booster."
- Phosphorus fertilizers or soil conditioners can be used at planting, but avoid other granular or water-soluble foods before bulb flowering. After blooming, these fertilizers can be applied judiciously to help replenish energy depleted during blooming.
Summary
If your bulbs fail, determining the leading cause is critical for avoiding similar problems in the future. Take time to investigate the affected area to look for signs of rotting or potential predation. You may be surprised to find healthy bulbs beneath the soil that need more time to grow and flower. In poor soil conditions, replanting the same type of bulbs in the same spot may also result in another failure. Therefore, trying to deduce why they may have failed in the first place is the best first step to achieving healthy blooming bulbs in the future. If you are planting in a low, wet area, use raised beds for your fall-planted beds. Please remember, we are always glad to assist you with suggestions and troubleshooting advice if your bulb plants are not performing up to their potential.
