Reserve 21 is the name given to our garden based on the relative high number of different wildlife, especially butterfly, species that live in it and visit it.
Please read in conjunction with other related butterfly blog posts and photographs of British butterflies on this website.
The inventory in the table below is only of those plants in Reserve 21 that are known, via the literature, to be either important nectar sources for adult butterflies or host plants for butterfly larva (caterpillars). The excellent UK Butterflies website has two much more complete list of important nectar plants and larval plants that can be ordered by either, the common or scientific plant name, or by butterfly species.
The inventory table categorises the plants based on their basic horticultural classifications. Perennial plant species are first in the list such as trees, shrubs and climbers, and each of those are further broken down into sub-categories of whether they are deciduous (shed their leaves during the winter) or evergreen (have leaves all year).
Then come the herbaceous perennials, which are plants that live for multiple years like shrubs etc, that's aerial, above ground, parts die each year after flowering before shooting again from the ground during the next growing season. They do this because, unlike trees and shrubs, herbaceous plants are, by definition, have non-woody stems. These are the most numerous in terms of both nectar source and host plants.
The next category are herbaceous biennials which are similar to herbaceous perennials except that generally only have a life span of 2 years, in which they put on vegetative growth and become established in the first year and then in the second year they flower, set seed, and then the complete plant dies. Finally annuals are herbaceous plants that complete their lifecycle from seed to seed in one year.
The inventory table lists the 66 different species of plants that grow in the garden of Reserve 21, of which 58 are suitable nectar sources for UK butterfly species, and 19 are suitable as host plants for the larva of UK butterflies.
The inventory is dominated by those plants that provide nectar - the key reason why butterflies visit gardens and as explained in my blog How to Attract Butterflies and Influence them.
Of the 19 plants in the garden that are potentially suitable for the larva of UK butterflies it's anticipated that only 4 are probably actually host plants and play a role in the breeding of butterflies in the actual garden.
I have seen eggs laid on the underside of broccoli leaves in the garden, of either the Large White or the Small White butterfly. The large number of reasonably sized holy bushes in the garden, together with the Holy Blue being one of the most popular butterflies in the garden, suggests that it is breeding in the garden, especially as ivy also grows in and around the garden, upon which their larva also feed.
The Orange Tip butterfly is a regular visitor and, given that the garden has at least two, albeit small, patches of hedge garlic, it's also possible it breeds in the garden too, but being a strong flying mobile butterfly it might be breeding in colonies located in the area where there are higher quantities of its host plants present.
It should be noted that the species of butterflies listed in the in the larva host column in the table below, are not definitive and based only on one source of information. It might be that more of the plants listed are used as hosts by the larva of UK butterflies.
Also those species highlighted in bold in the larva host column are species that are known to visit the garden, but as explained above, are unlikely to breed in the garden on these host plants, except the Holy blue, Small and Large whites and possibly the Orange Tip.
Finally the table is incomplete in that I haven't finished indicating the flowering periods for every plant species listed. I will do this in the next update of this blog article!
References
https://www.ukbutterflies.co.uk/nectar_sources.php
https://www.ukbutterflies.co.uk/foodplants.php