Native Willow versus Productive Willow

We offer a range of willows to suit all uses and interests. Here’s a handy guide to the differences between them:

Productive biomass willow varieties grown as Short Rotation Coppice

These willows are the highest yielding, quickest growing and cheapest option. They all have been bred by plant breeders and typically involve at last two different species in an interspecific cross. Many involve European species such as Salix viminalis and S. dasyclados often crossed with related species from Russia/Siberia or Asia. The elite lines of interspecific crosses tend to exhibit Heterosis – this means that the best selections amongst the progeny of a cross are superior in many traits compared to the parental species.

A biomass variety will have been screened over a number of rounds of field or laboratory selection at multiple sites in the UK and Ireland. They are evaluated for characteristics such as yield, disease and pest resistance, and erect growth. Any variety on the market therefore is an elite line that is typically and literally head and shoulders above other non-tested or unbred willows.

They are sold as cuttings and rods. Multiplication is a simple process and a grower buying this material in bulk will pay a lower price than other options.

It takes a minimum of 10 years to produce, test and multiply a new variety. This is a major undertaking and therefore breeders tend to protect their intellectual property by registering the variety for Plant Breeders’ Rights. This means that a buyer of a cutting or a rod cannot multiply this variety without the breeder’s permission.

In order to guard against pest and diseases biomass willow varieties tend to be planted in mixtures. It is never a good idea to plant a single block of one variety. Biomass willows tend to be of a very even yield standard so there is less chance of a variety being outcompeted by another.

Biomass willows can be used for virtually any Willow Solution.

Native clones of willow

There are many willows that have names but are not varieties. Generally, they are willows that have been selected for a useful purpose be that basketry, hurdle production, cricket bat manufacture etc. These would normally be a single tree of shrub discovered in nature that has been reared as cuttings and sold as a named clone. Some of the best ones are multi-species hybrids that have occurred naturally.

Generally, these clones are useful and can serve a purpose. Many are native. As there are lot of alternatives, they tend to get multiplied in small amounts. As a result, the cost of native clonal rods and cuttings tends to be higher than biomass willow varieties. They are not covered by Plant Breeders’ Rights so they have the advantage that a grower can multiply them.

As these clones have not been bred or selected, they tend to be a lot lower yielding than biomass willows. This will also mean that they take longer to achieve the outputs of a desired Willow Solution. In addition, with certain applications they will achieve poorer results. For instance, the growth rate and size of native willow clones will make them inferior at flood mitigation and biofiltration. They will do the same job but less well. Put in another way; in order to do the same job as biomass willows, they would take up more land cost more money and take longer to do the job.

Native clones of willow can be used for virtually any Willow Solution. However, a mixed plantation of native clones is more likely to be problematic in terms of competition between higher yielding and lower yielding material so material should be selected for synergistic benefits. .

Native species of willow

We also supply plug plants that are pure native species from known provenance. Each plug plant is a unique individual, and each batch of plug plants will show a typical population bell curve. In terms of a phenotypic trait such as height, this means that there will be some short ones, some tall ones and a lot that are in the middle.

As the seeds that have been reared into seedlings come from individual trees, the only thing we know about is the characteristics of the maternal parent. Most of the seed will have been gathered from healthy maternal trees but we have no idea of the male parent as this will only be known to the bee or other pollinating insect that did the deed!

There has been no testing of native species plug plants. The first test will be when you plant it. The plant wants to grow and will grow if you have made necessary land preparation to reduce weed competition. The yield will be a lot lower than native clones and significantly lower than biomass willows. As such it will take a lot longer and a much greater area of land to achieve a desired Willow Solution.

The native plug plants are the most expensive option, but one advantage is that they already have roots so as long as it is planted into a weed free seed bed it should grow away nicely.

Another advantage is that as native species are sold as populations there is a degree of resilience to pests and disease. However, best results will be achieved when native species of willow are mixed with other species.

Summary

Below is a summary of the different types of willow. A five-star rating is the best with a one-star rating as the lowest.

We can supply any type of willow to suit your needs. However, if you wish to achieve a Willow Solution quickly, produce the highest biomass yields, take up the least land area and at the lowest cost then we highly recommend using biomass willow varieties.

*Please note: there is nothing to suggest that biomass willow varieties are any less advantageous to biodiversity than native species. The genus Salix is a 40-million-year-old genus with very light seeds that travels large distances on the wind. In our experience of dealing with biomass willows we have not visualised any degree of preference amongst insects, other invertebrates or birds in biomass willows compared to native willows. The reason for the 3* rating is that currently most biomass willow varieties are female and these only provide nectar. Male trees provide both pollen and nectar. The reason that most biomass willow varieties are female is that there is genetic dominance for 100% female progeny in the F1 generation. In addition, female varieties have tended to be higher yielding and therefore the ones selected. Breeders are endeavouring to select more higher yielding male varieties to increase the options for growers.