Hemlock, hemlock, Tsuga canadensis – care

There are various small trees for everyone who finds a normal Canadian helmlock in the garden too big. They grow normally upright, but also as ground cover and as a hanging form.

Tsuga canadensis

• ‘Nana’ – pillow form, slow growing, long branches that grow prostrate and horizontal, short dark green shiny needles, annual growth 4 to 5 cm
• ‘Baloony’ – witch’s broom, grows very slowly and densely, initially spherical, later cushion-shaped, slightly overhanging twigs, light green needles, annual growth 5 to 7 cm, after 10 years about 70 cm tall, good for containers
• ‘Frosty Ice’ – dwarf form, pyramidal and slow growth, short green needles with white tips, annual growth 4 to 6 cm, after 10 years about 60 cm high and 30 cm wide
• ‘Cole’ – dwarf form, ground cover, grows slowly and densely, overhanging twigs, short light green needles, very robust, annual growth 7 to 10 cm, after 10 years around 20 cm high and 80 cm wide
• ‘Jervis’ – dwarf form, very slow and dense growth, initially spherical, later shaped like a sugar loaf, strong light green needles, very robust, annual growth 3 to 5 cm, after 10 years 50 cm high and 30 cm wide, good container plant
• ‘Microphylla’ – dwarf form, slow and dense growth, initially pyramid-shaped, later it gets a crown, short dark green needles, very robust, annual growth 10 to 12 cm, after 10 years 100 cm high and 40 cm wide
• ‘Moll’ – creeping cultivar, medium strong and very dense, initially flat and somewhat spherical, later becoming broad and bushy, short, dark green needles, robust, annual growth 7 to 10 cm, after 10 years 50 cm high and 100 cm wide
• ‘Pendula’ – hanging form, grows slowly and very densely, twigs all hang vertically downwards, short dark green needles, annual growth 15 to 20 cm, after 10 years about 150 cm high and 60 cm wide
• ‘Minuta’ – dense miniature form that grows very slowly, initially grows in a flat, spherical shape, later becoming somewhat pyramid-shaped, short, dark green needles, robust woody plant, annual growth is only 1 to 2 cm, after 10 years it is around 20 cm high and 20 cm wide
• ‘Stewart’s Gem’ – dwarf form, very slow and dense growth, initially spherical growth, later flat spherical, short light green needles, robust wood, annual growth 3 to 4 cm, after 10 years 20 cm high and 30 cm wide
• ‘Watnong Star’ – dwarf form, grows very slowly and densely, initially spherical habit, later umbrella-shaped, short dark green needles, robust, annual growth 2 to 4 cm, after 10 years 20 cm high and 30 cm wide

The care of the hemlock

Hemlocks don’t fit everywhere. You need a good location and suitable substrate. Also, the size that they can reach should be considered. The roots also need space accordingly. Initially, hemlocks grow slowly, but later 40 cm annual growth is not uncommon. They are therefore not suitable for small gardens. In addition, the trees are sensitive to windthrow. That too must be taken into account. The slow-growing dwarf varieties, of which there is a good selection, are often better. Large hemlocks look best as solitaires. They are also often used as high hedges, as they tolerate pruning very well. They are often planted where yew hedges are out of the question because of their toxicity.

Helmlock firs do not tolerate heat very well and should be planted in cool places with slightly higher humidity. They like soil that is not too dry, deep and loose. The trees are best planted in autumn. They need a lot of water, especially in the first two to three years until they grow. The hemlock looks best without pruning, but it tolerates pruning. However, it no longer sprout from old wood. Propagation is by sowing. Diseases and pests do not appear often.

location

The location should be neither too sunny nor too shady. Both extremes are unfavorable. Partial shade is ideal here. Since larger specimens are sensitive to windthrow, a sheltered spot is good. The root system does not go deep, so a hemlock can fall over in a storm, literally tearing the root out of the ground. Normal wind does not matter, but storms are not without and they are increasing, as we have found out in recent years.

• Preferably in mountainous locations, up to 1,700 m
• partial shade
• Loves cool and humid locations
• Too sunny locations weaken this fir. She is sensitive to heat.
• Places that are too shady let them go bald
• Sheltered from the wind, since the branches are rather delicate
• No east wind
• Never dry location – needles yellow

plant substrate

Hemlocks make some demands on the plant substrate. They like deep, nutrient-rich soil that shouldn’t be too heavy. The trees do not like permanent wetness or soil that is too dry. If it is permanently wet, there is a risk of root rot, if it is dry, the needles will fall off. The tree is bare.

• Deep, nutrient-rich substrate
• Well-watered loamy soil that should not be too heavy (mix in sand if necessary)
• Basic to acidic
• Low in humus and lime
• Permeable but moist
• no waterlogging
• Preferably in mountainous locations, up to 1,700 m

plant

There is nothing unusual to consider when planting. The root ball should be sufficiently watered before planting. It is best to submerge it completely under water until no more air bubbles rise. If the soil is very clayey, this should be mixed with sand. A thick layer of sand at the bottom of the planting pit also makes sense. It serves as drainage.

• Plant in autumn or alternatively in spring
• The Helmlock fir looks best as a solitaire
• Planting distance depends on the size of the trees
• Actually, a planting distance of 1 m is sufficient, but then it takes a few years for the sides to close
• Usually 2 to 3 plants are planted per meter
• But two are enough, the gaps are closing up quite quickly.

watering and fertilizing

The water supply is important. In the first two to three years after planting, special care must be taken to ensure that the soil does not dry out in the long term. However, even older specimens do not get along well with drought. Dry damage is quite common. They are easy to spot. The needles just fall off. The tree looks pretty bare.

• Water the young plants sufficiently for the first two to three years, in particular, until they are fully established
• Water when dry, as the superficial roots quickly suffer from drought
• Drought is not tolerated. The first needles fall quickly and under certain circumstances all of them can fall off. The tree is bare.
• Coniferous fertilizer is suitable as a fertilizer, preferably one that contains only organic nutrients, because hemlocks are sensitive to salt.

To cut

Hemlocks tolerate pruning well, but thrive and perform best when left to grow without pruning. The trees reliably sprout again from young wood. If you cut branches that are older than 3 or 4 years, you are usually unlucky. These old branches no longer sprout.

• Very tolerant of pruning, which is why the hemlock is occasionally used as a hedge plant
• It is better to only cut the one-year-old wood
• The tree does not always sprout from perennial wood.
• Hedge trimming – June to September
• The special breeds should not be cut, otherwise they lose their special growth.

hibernate

Hemlocks are sufficiently frost hardy. They usually do not need any winter protection.

In very cold areas, however, it is advisable to pack up the top shoot of the tree in autumn to protect it from freezing. Of course, that only works as long as you can get to him. Above a certain height it becomes difficult. If the leading shoot freezes, it doesn’t matter, the crown then only continues to grow in multiple shoots. The shape of the tree changes. This can be remedied by removing the side shoots. Covering the root area is also beneficial for young plants. Bark mulch is usually sufficient. You simply pour a little more than usual in the fall.

multiply

Hemlocks are propagated by sowing the seeds. It is important that the seeds are stratified, because they are cold germs. This can be achieved by sowing directly outdoors or by placing the seeds in the refrigerator for about 6 weeks. The special breeds such as the dwarf shrubs can usually only be propagated vegetatively, mostly by cuttings. This method is not easy, which also explains the rather high prices of the trees.

• Soak the seeds in lukewarm water for about 24 hours
• Sow in coconut fiber or potting soil
• Keep the substrate constantly moist, but never too wet
• The germination rate is low.
• It also takes a long time for the seedlings to develop into small trees.
• Seed remains germinable for 4 years

diseases and pests

Hemlocks are strong and resilient. However, in recent decades, Helmlock mealybugs, imported from Asia, have multiplied and spread rapidly. Their infestation leads to needle and shoot damage and can also lead to the death of the trees after a few years.

If the needles turn yellow, a fungal infection may be the cause. Older needles will turn brown and fall off prematurely. If the infection occurs for several years in a row, all the needles can fall off. You can prevent this by not planting the trees in places with high humidity. It is often the fungus species Fusarium or Rhizoctonia. Especially seedlings fall victim to it. The infestation can be recognized by the fact that the roots are greyish to whitish in colour.

• Fungal infections can usually be identified by the fungal spores found on the underside of the needles.
• They often occur in wet weather.
• Weakened shrubs and seedlings are particularly susceptible
• Antifungal products can help
• Affected branches can also be removed.

Frequently Asked Questions

How big will the hemlock root get and how far away from buildings should the trees be planted?
Helmlock firs are flat-rooted and develop a large, well-branched root system over the years. The strongest roots reach about a meter deep. On the other hand, the small, superficial roots can spread up to 10 m in all directions. The distance to the house should be at least 7 m.

Is the hemlock poisonous?
Although I have read on several forums that the fir is said to be poisonous, I have not found anything about it in the specialist literature. On the contrary, the helmlock is recommended as a good alternative to the yew, precisely because it is not poisonous like the yew.