The royal frost birch tree (Betula ‘Royal Frost’) is a popular variety known for its striking white bark and attractive red-purple foliage. However, like all trees, it can be susceptible to certain problems if not properly cared for In this article, we’ll discuss some of the most common issues royal frost birch trees face and how to prevent them.
Bronze Birch Borer
One of the most notorious pests of birches is the bronze birch borer. This insect larva bores into the bark of stressed or damaged trees, disrupting nutrient flow and eventually killing branches or the entire tree. Evidence of borer damage includes D-shaped exit holes in the bark and cracked, peeling bark.
Keep your royal frost birch healthy by sitting it in the right place, watering it, and fertilizing it. This will keep borers away. Lawn mowers and trimmers should not cut into the bark. Preventative systemic insecticides labeled for birch borer control can be used. If you catch an infestation early, you may be able to save the tree by cutting out the infected wood and treating it with insecticide. But trees often can’t be saved after a lot of damage.
Leaf Spot Diseases
Royal frost birch is prone to several foliar diseases, including leaf spots caused by fungi. These diseases manifest as small brown or black spots on the leaves, sometimes with yellowing halos. Severe infections can defoliate the tree.
Leaf spot fungi thrive in warm, humid conditions. To keep them away, pick a spot with good air flow and morning sun to dry the leaves quickly after it rains or sprinkles. Avoid overhead watering. Pick up and throw away the leaves to get rid of the spores. Apply appropriate fungicides at the first sign of infection. Ensure proper tree spacing to allow air movement between canopies.
Aphids
Aphids, which feed on tree sap, can get into royal frost birch trees like many other trees. These tiny bugs gather on young shoots and the undersides of leaves to get plant fluids. Their feeding causes curled, stunted leaves and sticky honeydew drippings. Sooty mold may follow, coating leaves in dark fungus.
Check birch trees frequently for aphid colonies. Knock them off with a strong spray of water, or apply insecticidal soap. Ladybugs and other beneficial insects help control light infestations naturally. You can also use aphid-targeting systemic insecticides applied as soil drenches or trunk injections. Be sure to get complete coverage of the foliage.
Environmental Stress
Royal frost birch does best in cool climates. In hot, humid southern areas, it may not do as well because it is more likely to get borers and diseases. Pick the right USDA Plant Hardiness Zone for the tree and make sure it gets regular watering when it’s dry. Cover the roots with mulch and give them shade. Roots like it cool and wet. Do not overwater, dry out, or compact the soil. Also, do not damage the bark or roots.
Trunk and Branch Damage
The papery white bark of royal frost birch is delicate and easily injured by mechanical wounds, sunscald, animal feeding, and improper pruning cuts. Wrap young trunks to prevent winter damage. Paint wounds and pruning cuts with tree sealant. Cover bark with tree guards if deer or rodents are a problem. Hire an ISA Certified Arborist to properly prune branches without tearing the bark.
By selecting suitable growing conditions and providing attentive care, you can help prevent problems and keep your royal frost birch healthy and thriving for years of beauty. Be vigilant for signs of pests or diseases and take prompt action at the first indication. With its graceful form and multi-season appeal, this elegant tree is worth the effort to maintain.
To create a multi-stemmed birch:
- Pick a young plant that is less than 1 m (3²ft) tall and cut it back either close to the ground (but not below 8 cm or 3 in.) or 30 to 60 cm (1-2 in.) from the ground.
- Cut the stem horizontally and smooth out the wound so there are no rough edges. This wakes up dormant buds that should grow strongly the following year.
- After one or two years, pick three to five strong, evenly spaced shoots and cut off any weak or extra shoots that grow to the base. This will reduce the number of main stems.
- Don’t rush to cut off the stems of lower branches until the main stems are already strong.
Some nurseries and garden centres will supply multi-stemmed birches ready pruned and trained for planting. However, by planting two or three young plants in the same planting hole you can achieve the same results. If they are sapling size (up to 1m/3¼ft tall) they should need no staking and you will have more control over the placing and arrangement of the stems.
Birch species can be grown from seeds that are planted right away in the fall or that are kept in the fridge all winter and then planted in February.
- Seed has relatively short-term viability so avoid old seed
- Named cultivars will not come true from seed
- Make thin rows on top of the compost or cover very lightly.
- Germinate at 10-15°C (50-59°F)
- Put the plant in a pot when two leaves have appeared, and keep putting it in pots to keep the growth going. This is one way to get a tree 1. 2m (4ft) tall by the end of June.
Named cultivars are propagated from cuttings or by grafting. Neither technique is particularly easy for the amateur. Commercial nurseries regard a 50% strike (successful rooting) rate as good for cuttings.
- Take softwood cuttings up to 15 cm (6 in) long from the middle of spring to the beginning of summer.
- Using a rooting compound, put the cuttings into cuttings compost that doesn’t hold water, and cover them with a plastic film tent to keep the moisture in (commercial nurseries would use mist systems).
- Provide bottom heat of 18-24°C (64-75°F)
- Rooting should occur in 6-10 weeks. Feed regularly once rooted to ensure strong growth.
- Keep a little dry over the winter, and pot up in the spring.
From late winter to early spring, birches can be grafted onto Betula pendula rootstock or, if that doesn’t work, B nigra.
Birches tend to establish quickly and make rapid growth for the first 12-15 years. This will give a feeling of maturity to even relatively new gardens.
For more ideas on choosing birch and where to buy them, see our RHS Find a Plant.
What is a Royal Frost Birch Tree?
FAQ
How do you take care of a royal frost birch tree?
Keep the tree consistently moist and consider using soaker hoses and bark mulches to keep the root zones cool and moist. It needs little pruning, but if necessary, you can prune during the dormant season. Do not prune in winter or spring when the sap is running because it will bleed.
What are the disadvantages of birch trees?
Perhaps the biggest drawback to Birch is there root system. These plants are native to areas near rivers and streams, so they never grow deep roots. Because of this, they almost never reach the water table, and during times of extreme drought, they could die from not having enough water.
What does a diseased birch tree look like?
Brown or black spots on leaves that aren’t round or oval, sunken tan to red-brown sores on stems, and early leaf drop are all signs of this disease. In severe cases, cankers can form on branches, and fruit can exhibit dark, sunken spots. Treatments: Remove and discard infected leaves and branches.
How fast does a royal frost birch grow?
It grows rapidly, adding 3 feet a year when young, and reaches 30 or 40 feet tall and about 20 feet wide.