Box (Buxus) is also one of the early risers and new growth may already be appearing if the weather warms. But it’s not too late for a few Spring jobs. Here are some suggestions:
Moving or re-potting box.
Best to move box in late winter/ early spring, when the plants are semi dormant and there is still plenty of moisture in the soil. Re-potting can be done later but avoid doing this is in warm, sunny weather as the roots can dry out quickly and damage the plant.
Hard Cutting and Shaping
Box can be hard cut back to old wood. This stimulates new growth and the box should recover quickly – one of the reasons why the plant is so good for topiary. Renovation work like this is useful to reshape box and is best carried out in early Spring, when the risk of hard frosts has passed.
Mulching provides a good environment for healthy root growth, which in turn leads to healthier, stronger plants. Mulching also retains some of the moisture in the soil that has built up over the wet winter months, helping the Buxus to cope better with the drier conditions of Summer. Mulch can be a good compost, leaf mulch (not much nutrient content) or a product such as Strulch.
Spring is a good time to apply a slow release granular feed around the base of the plants, giving the new growth a helpful boost of nitrogen. Vitax Buxus Feed and Topbuxus Grow both work well. Best to apply the feed after the risk of hard frosts has passed as new growth can suffer in very cold conditions.
Start applying a foliar feed nearer the end of Spring. I like to use seaweed extract or Topbuxus Health Mix. Add to water and spray on to the leaves of the box. Continue to do this every 4 to 6 weeks during the growing season (May to September).
Box tree caterpillars can over winter on box plants and Spring time is when they emerge and begin munching on the box leaves. Check the Buxus carefully as the caterpillars are often well hidden within the plant. Dispose of any caterpillars when found to prevent them becoming moths and creating the next generation of this destructive pest.
The weather is starting to warm up but Spring can still be wet. This is the perfect conditions for fungal growth so be vigilant for blight outbreaks. An area of blackening foliage is often a good indicator of blight. Spray this area as soon as possible with a fungicide such as Provanto Fungus Fighter to prevent the blight from spreading. If caught early then there is a good chance the box will recover. But always keep an eye on your box plants as the blight may return in the Autumn.