I would like to use native plants to create a more ecologically interesting habitat. How do I start?
There are two key questions you must answer.
Firstly, what is the environment that you are starting with? Where is the site located, what is its aspect and altitude? Is it sunny or shady, wet or dry, flat or sloping, what is the soil type, what is its pH and its fertility levels? Is it a habitat that just requires enrichment or do you need to create a completely new landscape?
Secondly, what are your objectives for the site? The answers to these questions help define the range of habitats that can be created. You may want to create an attractive garden using mainly native plants, or your aim could be to re-create, as far as possible, a version of the wild habitat, or something in-between. Some people want an educational resource, others a butterfly meadow.
How can I get my soil tested, what is the key information I require?
Take samples by walking a ‘W’ across the site and at each point of the W take a soil sample from 7-10cm depth (3″-4″). Mix the soil together and send about 500 grams (1 lb) to us for analysis. Soil should be analysed for texture, Phosphate, total Nitrogen and available nitrate.
The soil type, pH, fertility and water status (very freely drained, moderately drained, periodically waterlogged etc.) and the levels of light on the site will determine which species will thrive.
Broadly pH below 5.5 is acid, 5.5 to 7.5 is considered as neutral, while above pH 7.5 is alkaline. Most truly wild flowering grasslands have Phosphate readings of between 5 and 15 ppm (parts per million).
When P readings are below 15 ppm, or less index 1 and below (using Olsen’s extractant) then the soil is infertile and ideal for wild flower establishment, but projects can still be successful, particularly using plants at P readings of 30 ppm, i.e. below index 3. Two Nitrogen analyses can be carried out to indicate soil fertility. If total Nitrogen should be below 1700 ppm then the site is relatively infertile. Similarly, when easily extractable nitrate is measured below 10 ppm, the site’s fertility will be relatively low.
Low fertility is ideal for species diversity but moderate fertility does not preclude wild flower establishment. Problems can be countered by higher management inputs in early years (e.g. mowing and removing cut material 3-5 times each year) and by species selection. As a rule of thumb the larger or taller the plant the greater its capacity to compete in the more fertile soils. Good examples are Meadow Cranesbill, Black Knapweed (Centaurea nigra), Tufted Vetch (Vicia cracca) and Meadow Sweet (Filipendula ulmaria).
Really Wild Flowers can carry out the soil analysis on your behalf. This service provides the analysis results plus recommendations on species and management. (See Soil Analysis service)
Why is soil fertility such an issue?
Broadly speaking, our native flora evolved in a time before artificial fertilisers, and although they do grow quicker with fertiliser, other species grow so much quicker that wild flowers tend to get out-competed. Wild flowers are used to problem conditions. Grassland plants in general require low fertility soils but there are species which because of their size or vigour can sustain themselves in quite fertile conditions, provided they are given the right start (i.e. free of perennial weeds, only non-invasive grasses to compete against, frequent cuts in the establishment year and intensive cutting in subsequent years). Some species perform best under shade, while other plants require damp or waterlogged soils.
Although we can carefully select the most appropriate species range based on the site, soil etc. wild flower plants are idiosyncratic and even though all the conditions theoretically appear right a small proportion of the selected species may fail for reasons such as slugs. Generally wild flowers thrive when they are in the right place, and die out rapidly when planted into an inappropriate site.
What other clues are there as to which species are likely to be successful?
Rapid surveys of local ‘wild’ habitats will often reveal which native species thrive. Local ‘floras’ provide other clues. Do not hesitate to ask local Botanists and experts in the Local Wildlife trusts. They will often be able to list native species and even the likely National Vegetation Classification for your area – which can be used to draw up species listings (see Publications in Downloads).