Dahlias failing to bloom may indicate errors in one or multiple aspects of their care, including lighting, watering, fertilization, pruning, or disease prevention.
In the world of gardening, few flowers are as captivating as dahlias. However, these sensitive plants can be finicky, requiring careful attention to detail to ensure a bountiful bloom.
Dahlias often fail to thrive due to a handful of common issues. Overwatering or underwatering, excess nitrogen in fertilizer, inadequate sunlight, too cold temperatures, failure to deadhead spent blooms, and physical damage or stress to the plants are the primary culprits.
Watering problems, whether too much or too little, can cause yellowing or wilting leaves and prevent blooming. Overwatering can lead to droopy, translucent leaves from root stress, while underwatering deprives the plant of needed moisture. Deep watering once or twice weekly with good soil drainage and mulch helps maintain healthy blooms.
Fertilizers high in nitrogen promote lush leaf growth at the expense of flowers. Dahlias need a balanced or potassium-rich fertilizer to encourage vibrant flowering rather than excessive foliage. Applying a bloom-supportive feed through the growing season aids flower development.
Dahlias require full sun to bloom well. Insufficient light hinders bud formation. Persistent dull weather can delay flowering, but flowers will usually follow once the sun returns.
Temperature sensitivity is another factor to consider. Dahlias do not grow or bloom well in cold soil or air temperatures. Tubers remain dormant below 55°F (13°C) and can rot if planted too early in cold, wet soil.
Removing spent flowers (deadheading) encourages plants to produce more blooms rather than seed. Deadheading is important to make room for new blooms and prolong their flowering period. A clean, sharp pair of snips, like the Darlac Compact Snips, is recommended for deadheading dahlias.
Broken stems from wind or heavy rain, or damage to tubers and root systems, can reduce blooming ability. Providing proper staking and support helps prevent breakage and stress that could impede flowering.
Slugs can also pose a threat to dahlia shoots and flowers, causing buds to disappear. Copper tape can deter slugs from damaging dahlia plants.
Dahlias are sensitive plants, so care should be taken to avoid mistakes that might hinder their flowering. A fertiliser like Vitax Dahlia Feed, available on Amazon, is designed to promote strong growth and plenty of flowers. The current dahlia season has started for most varieties.
Sophie King, the Gardens Editor, joined the team in June 2024. Sophie, always on the lookout for the latest garden trends and enjoying sharing growing hacks for every space, has a love for gardening and has tried growing various vegetables and flowers. David, a fellow gardening enthusiast, recommends removing dead flower heads to encourage more blooms.
Remember, with the right care and attention, dahlias can reward you with a stunning display of colour in your garden. Happy gardening!
Watering issues, whether over- or underwatering, can affect the health of your dahlias, leading to yellowing or wilting leaves and potentially preventing blooming. A correct watering routine involves deep watering once or twice weekly with good soil drainage and mulch to maintain healthy blooms.
Fertilizers that are high in nitrogen can promote an excessive amount of foliage instead of flowers for dahlias. To encourage vibrant flowering, use a balanced or potassium-rich fertilizer and consider applying a bloom-supportive feed throughout the growing season for optimal flower development.
