Alder - Grey (Alnus incana)

Our range of Grey Alder (Alnus incana) bare root trees

We have Alnus incana bare root plants in several specifications.  The 1+0 specification plants are seedlings (often called whips) which were grown from seed sown in the spring and are sold during the following November to April months ie they are 1 year old.  We have Alnus incana whips in several heights.

You can read more about the specifications we offer on the tab just below the pricing table to the right of this product description.

Grey Alder (Alnus incana) Summary

Grey alder is a small to medium sized conical shaped tree, identified by its smooth dark grey bark, and a really useful tree for difficult sites where little else will grow.  Like other alder varieties it is good in wet boggy soils but unusually this variety is particularly good in really dry thin soils (like the sides of hills) and will grow well on sites alongside mountain streams.  It is often used to reclaim spoil heaps, railway embankments and derelict land.  As with other Alder varieties, it has nitrogen fixing capability so is particularly useful on poor infertile soils where it will gradually lead to soil fertility improvement.

It was introduced to the UK about 200 years ago and originates from the Caucasus.

Soil and situation

Grey alder is light demanding but will tolerate partial shade.  It does well on most soils but is particularly useful on dry stony slopes and scree.

Leaves, flowers and fruit

The leaves are alternate, dark green, ovoid, about 10cm long, sharply pointed with serrated margins and are grey and velvety underneath.  Alders produce conspicuous male yellow catkins in early spring (before the leaves) in clusters of 3 or 4, which are good for pollinating insects (and an excellent source of very early pollen) and hard woody cones (called strobiles) in autumn first green turning brown (which contain seeds popular with birds) which often stay on the tree throughout winter.  Unlike Alnus glutinosa and Alnus cordata, Alnus incana has no sticky parts.

Eventual height and growth rate

Grey alder is a vigorous tree or multi stemmed shrub. The usual eventual height is about 10- 20m and it has a fast growth rate.

This section gives definitions on the specifications of plants that we sell.  We are specialists in field grown (or bare root) plants which are grown in two ways.  The majority are grown from seed, some are ready within one growing season (seedlings or 1+0's) and some species require two growing seasons (1u1's).  In addition to growing from seed we also grow from small plants or cuttings (transplants) which are much more widely spaced (taking more land, more irrigation water, fertilisers and labour).  There are only a handful of bare root wholesale nurseries in the UK and of those even fewer grow transplants but Ray Jenkins has many years' experience of transplanting so we grow these in large volumes.  Ray has written this blog about the benefits of bare root plants and how they are grown and another blog which gives further detail on bare root specifications.

The detailed specifications are shown below.  If you are in doubt about what specification to use please email us on enquiries@rjtreesandhedging.co.uk with a description of the project (and photos if appropriate) and we will advise you.

1+0 - field grown in one season from seed, known as a seedling (sometimes called a whip), generally a slender single stem plant.   These are the cheapest specification and are particularly suitable for planting where weed competition will be less intense, soil is shallow or on exposed windy sites.  Gives a high root to shoot ratio and minimal plant "check".

2+0 - a 2 year seedling, field grown from seed in the same seed bed in two growing seasons where the species cannot be grown to a saleable plant from seed in one season

1U1 - 2 year old plant called an undercut, field grown for two seasons in the same seed bed and undercut by machine (a sharp blade cutting the roots under the soil level) after the first year to develop the root structure. We do this with several species which take 2 years to develop (eg oak, beech, hornbeam)

1+1 - 2 year old plant (transplant) grown from seed in the first year and then transplanted into a different area of the field and spaced out for the second growing season - a robust plant with a larger and more robust root system than seedling or undercut plant which will enable it to better withstand drought and weed competition. Often the best choice and the staple norm for farm hedging and this specification is a requirement of the Countryside Stewardship Grant

1+2- a 3 year old plant, two years field growing in the seedbed and then transplanted (and spaced out) for a further two growing seasons giving a tall, stocky, bushy plant

2+1- a 3 year old plant, two years field growing in the seedbed and then transplanted (and spaced out) for a further growing season, giving a strong bushy plant

3+1 - as above but field grown for a further growing season for more height and a very bushy plant

1+3- 4 year old, one year field growing in the seed beds and then transplanted (and spaced out) for three years, giving a very strong, bushy plant

2+2- 4 year old, two years field growing in the seed beds and then transplanted (and spaced out) for a further two years - a very mature plant suited to certain species like beech and hornbeam where we can offer almost instant hedging

and some that are a bit different.....

P9 - a plant grown in a greenhouse or polytunnel in a 9cm pot (for holly which germinates poorly in the field)

Cell grown - a plant grown in small deep cells (like a small yogurt pot) and then lifted out of those for transportation. Commonly used in forestry and large hedging projects.  Very high quality plants with excellent success rate.  See our blog on the benefits of cell grown plants.

C+1 or C+2 - a 3 or 4 year old plant initally started as hardwood cuttings grown on for a year as cell grown plants and then lined out in fields to grow on for a further 1 or 2 years (a technique used for Cherry Laurel)

0/1 - a hardwood cutting, then field grown for one season (for example for white willow, black poplar and osier)