Starting your own herbarium

Collecting and naming plants has its roots firmly in the age of exploration and colonial expansion of the 17th to 19th centuries. Whatever you might feel about this period of European history, whether it be admiration for the brave adventurers or shame at the greed driven, land and resource grabbing, colonisation of distant lands, British history is entwinned with seeking out new species of plants, recording them, and preserving them for future study.

Some of the oldest plant specimens held at Kew date from the 17th Century. Since that time Kew’s collection has grown to contain millions of species from many recognisably famous Botany icons like Joseph Banks and Karl Linn.

Starting your own collection of pressed plants is very easy and from a bushcraft-study perspective enables you to study a plant/s year-round (albeit in a very 2 dimensional way!) rather than waiting to encounter them during their particular months of growth or the requirement of travel to observe them within their specific environments.

This last point is particularly relevant to the flowers (which may only be present for a few weeks in some cases) and to those species growing in places you don’t visit often enough to learn them thoroughly in the way you would with a commonly encountered species.

Before we hit the how, it is worth passing on a few words of caution…
Firstly, you should never pick something which you cannot positively identify. If you were for example handling a highly toxic species such as Monkshood, Foxglove or Hemlock you would need to exercise caution in how you handle them, especially during pressing where the juices may get on your skin.

Thorough hand washing should be used where you cannot firstly identify the plant and know that it is safe to handle.

Secondly, think about the plant!

Should you be picking a specimen just to press it for your personal herbarium? Remember that under the Wildlife and Countryside Act 1981 it would be an offence to uproot any wild plant without landowner’s permission. This means we can pick the leaves, flowers or fruit of plants for pressing into a herbarium.

Additionally, be aware that even with landowner’s permission (even if you are that landowner!) some plants are protected out right in law and no parts may be picked, Bluebells (Hyacinthoides non scripta, would be a good example).

In summary then, only pick the aerial parts of very common and positively identified plants to begin your herbarium.

If you have the great fortune of a garden this would be a perfect place to start collecting and pressing the many weeds that will grown there, otherwise you will need to carefully and respectfully collect specimens from the countryside.

Pressing plants
Essentially there is not much you can get wrong here! The RHS detail their recommended way for pressing and preserving plants which would make them presentable as a more professional, establishment worthy, collection of plants.

Ultimately you can just squish your plant between some old paper sheets then cellotape it to a sheet of A4 with the name written beside it.

This may be a great way to build a teaching aid as an instructor of plant identification for example but lacks the satisfaction of creating something of beauty that you can enjoy adding to each season over many years.

One day your amateur collection might have some value to a local establishment or provide useful data to studies of the plants and their habits in your local area.

How to press
Positively identify the plant you intend to pick.

Pick the plants on a dry day, that way you are not starting at a disadvantage with the plants being soaked – avoid the early morning and evening in summer where there may be a lot of condensation.

Snip cleanly the leaves or flowers you intend to press, avoid just pulling where you may damage either your specimen or the rest of the plant that will live on.

Ideally, I like to get them straight into a portable plywood press. This allows me to quickly arrange the specimen to show off the features I’m trying to capture in the herbarium.

Lightly press the plants between sheets of old paper or card. Blue roll works okay as an initial absorbent material and I have not found that it discolours the specimens. Do not over press your collections where you may find a lot of liquid coming out and staining the specimen or making it unnecessarily difficult to remove from the paper later.

I like to photograph the plant I am taking an example of to remind me later of habitat details and collection location, initial colour before drying etc which I can refer to as needed.

Once home transfer the lightly pressed plants to fresh absorbent paper or card with an appropriate weight to continue flattening and drying your specimens – some more woody or fleshy specimens may require a substantial pile of books, bricks or unpaid parking fines to get them flat.

Depending on the liquid content of your collections they may be ready for mounting in a few days or require up to a few weeks with several changes of paper during that time to get them dry.

Another method would be to collect your samples on a short walk and keep them in a breathable container until you can get them pressed at home – a plastic bag would make them sweat and wilt very quickly.

NB you will get more inventive as time goes by and the ‘got to collect them all’ disease takes hold of you, between the pages of the ID guide you have with you is typical for on the hoof pressing… in between the insoles and base of your shoes is more of an acquired specialty.

How to preserve
Once you have your completely flat and dried specimen prepared its time to preserve it for hundreds of years like those at Kew!

Many sources recommend the use of PVA glue to stick the sample to pH neutral paper. I’ve only used this method a handful of times and although it is fast, fun, and effective I dislike the glossy sheen left by the glue covering all the samples in the resulting herbarium.

Instead you can buy special tape designed for delicate and sensitive fabrics or papers which has a pH neutral adhesive, this won’t adversely affect your specimen over time. With this tape you can create beautifully arranged samples of your plant all with a more natural colour, reflectivity, and texture (allowing for changes that occur during drying).

With this method you simply cut small strips of tape and place them at key points along the stem or leaves to hold them in place.

For heavier samples you can additionally stitch the plant stem into position and this is why I opt for a more expensive heavy weight card that means you can thread through it and knot securely on the reverse without ripping, as thinner card or paper would.

How to record
If you only intend to preserve a handful of plants and flowers in a collection as a teaching aid, then you can simply write the plant’s common and scientific names next to it, using the simple presentation on field courses to highlight important structural features of a species.

If, however, your aim is to start a more comprehensive herbarium it is worth aligning how and what you record about the specimen with the more formally recognised method so that it can be more easily and universally understood if it should ever be involved or donated for a larger collection or piece of research.

As minimum you should aim to record the plant’s common and scientific name, the family the plant belongs to, the collectors name, collection location and collection date. These details are typically presented in the bottom right hand corner of the presentation and often are recorded on a separate dimension-specified card, which is then mounted onto the page alongside the plant.

Final thoughts
Why bother!?

Take the carrot or celery family (the Apiaceae, formerly the Umbelliferae) for example. The flowering structures of these plants are one of their most diagnostically striking features, whereby even if you did not know the plant in question you would likely say it was in that family from the flower structure alone.

Well, other than the already mentioned access to the plants at any time of year and from a variety of environments all in one convenient place for home study, I have found keeping a herbarium is a great way to become more familiar with the shared features of related plants within one family.

This is a great way to test your plant ID skills by covering up the info cards on the bottom right of each presentation you can mix up a whole bunch of specimens (I can feel Botanists grimacing as they read this…) and then test not only your identification of each specimen but also its relationship to other specimens by genus grouping.

The ability to place a plant in its correct family even if you cannot identify its exact species is a powerful way to learn about plants and is best exemplified for practical bushcraft use by the book Botany in a Day by Thomas J Elpel.

Herbarium aftercare
Look after your collection.

Moisture and pests are your biggest enemies here. I like to keep mine in an airtight plastic tub along with a few of those little silicone pouches that pull moisture out the air, these can be replaced from time to time.

I am told that deep freezing your collection for 24 hours every 6 months or so is a great way to ensure anything that might be snacking on your preciously arranged plants is dealt with.

In practice I add to my herbarium often enough that I can visually inspect for any pests. Keeping the herbarium out of direct sun light is also a good idea to avoid excessive loss of colour from delicate flowers and leaves.

I hope this inspires you to have a go at starting your own collection, however basic or artistically complex you would prefer, it’s a satisfying craft and provides an additional way of learning about plants however you regard, value, use or rely on them.

Happy plant preserving!