Rose New Shoots Deformed? Causes & Fixes

A florist recently asked, “My roses are growing new shoots, but the leaves are very small and twisted in shape, not at all like normal leaves, what’s going on?”

Although this situation is not common, but there are indeed many flower lovers encountered similar problems. Today, we will analyze in detail the main causes of deformed new shoots in roses and provide corresponding solutions.

1. Severe nutritional deficiencies (especially micronutrients)

When the new shoots of roses are tiny, twisted, or even unable to unfold properly, it is most likely due to a severe deficiency of micronutrients.

Main causes

• Excessive soil alkalinity: The absorption of micronutrients by roses is strongly influenced by the soil pH. If the soil is too alkaline (e.g. using a lot of grass ash), it will affect the absorption of iron, zinc, calcium and other elements, resulting in poor development of new shoots.
• Case Sharing: There was once an in-ground planting of vine roses, due to the family’s mistake of applying a large amount of grass ash (strong alkaline), resulting in all the new shoots being deformed, while the surrounding roses that were not affected grew normally.

Solution

• Adjust soil pH: Use ferrous sulfate solution to irrigate roots and neutralize soil alkalinity.
• Supplement with calcium fertilizer: Calcium is essential for cell wall development, so calcium-containing fertilizers (e.g. calcium nitrate) can be applied.
• Avoid overuse of grass ash: Although grass ash is a natural potash fertilizer, overuse can raise soil pH and inhibit calcium uptake.

Note: If the problem is mild, roses may recover on their own over time (e.g., rain washing reduces alkalinity). However, it is best to intervene promptly to avoid prolonged poor growth.

2. Thin branches or damaged root systems

Even if soil conditions are normal, new shoots of roses may still be deformed, especially if the root system is damaged or the branches are too thin.

Main causes

• Transplant damage: Bare-root transplants or over-pruning of the root system can lead to insufficient nutrient uptake, which affects the development of new shoots.
• Competition for nutrients from weak branches: Strong branches will be prioritized to obtain nutrients, while weak branches are prone to deformed buds due to insufficient reserves.

Solution

• Pruning weak branches: Cut off stunted branches directly so that nutrients can be supplied to healthy branches.
• Promote root recovery: Use rooting agents after transplanting and keep the soil moist but not waterlogged.

3. Improper fertilization (fertilizer damage or nutrient imbalance)

Incorrect fertilization practices may also lead to malformed new shoots.

Main causes

• Concentrated fertilizer burns the roots: applying high concentration of fertilizer during germination will damage the root system and affect the development of new shoots.
• Preferential application of phosphorus and potassium fertilizers: Excessive phosphorus and potassium fertilizers will inhibit the absorption of calcium, resulting in deformed new shoots.

Solution

• Reasonable fertilization: Use balanced water-soluble fertilizers (e.g. 10-10-10) during the germination period to avoid overdose of a single element.
• Control the concentration of fertilizer: follow the principle of “thin fertilizer and diligent application”, avoid applying too much fertilizer at one time.

Recommended reading: For a more detailed guide to fertilization, please refer to the fertilization chapter of “Rose Care Book”.

Summary: How to prevent deformed new buds of roses?

• Regularly test the soil pH to ensure it is slightly acidic to neutral (6.0-7.0).
• Avoid excessive use of grass ash or lime to prevent the soil from becoming too alkaline.
• Prune weak branches properly to minimize nutrient wastage.
• Fertilize scientifically, using a balanced fertilizer during the germination period, avoiding strong fertilizers that burn the roots.

If your roses have already experienced deformed new shoots, you can check the above causes and take appropriate measures. Intervene in time, and the roses will soon return to healthy growth!