Aerial Herbs A-L
‘Aerial herb’ indicates the parts of a herb that grow above ground – from which the majority of indigenous herbal medicines are derived. In many cases you will find texts that conflict in their recommendations for either the leaf, or alternatively the whole aerial herb (complete with stems). Commercial suppliers have a preference for the latter (and will often supply the whole aerial herb even when described as leaf). There are also modern recommendations to use only the flowering tops, or more commonly to harvest leaves and flowering tops together, discarding the stems.
Harvesting & Preparation
In commerce there are purely pragmatic reasons to harvest just before the herb comes into flower. For small-scale production it’s usually recommended instead to harvest in full flower, partly as this usually yields the best quality in terms of biochemistry, and partly because flowering is the point at which the herb is likely to prove most manifestly energetic.
Most herbs are herbaceous (they die back in autumn and grow up again from dormant roots in the spring). In the main, these are harvested as the whole aerial herb from clean growth. Basal growth is likely to suffer from soil-splash, may have been blemished by soil-dwelling organisms, but in particular often exhibits ‘yellowed-off’ leaves, due to overshading by upper growth, particularly where herbs are growing tightly spaced. When you cut a herbaceous herb in this fashion, it’s recommended to ‘tidy up’ later by pruning back nearer to ground level, otherwise you may find dead stems intruding into a later harvest. Given that you are also putting the plant to unaccustomed extra effort, it’s advisable to treat it to a liquid feed at this point.
Non-herbaceous herbs such as Sage, Rosemary & White Horehound produce woody growth – harvest only the soft growth from the previous year, and leave about a third of it behind for good measure, otherwise the cut stems may die back or the whole plant may be killed. Trees and shrubs are usually more tolerant of pruning.
Whether herbaceous or not, there are only a very few examples (e.g. Thuja and Raspberry leaf) where the herbal material is stripped directly from the plant. The more normal procedure is to cut off the stems or branches, take them away to a convenient work station, and there complete any necessary stripping as part of the comminution process. When (as is common) only the leaves and flowering tops are needed, there is a trick to grasping the stems one at a time just below the upper soft growth, and stripping firmly downwards with the other hand to remove the leaves, then plucking off the soft (flowering) tip, in one smooth action.
Generally further comminution, if required at all, is easy in the case of aerial herbs as they usually present quite soft and un-resistant material. Take the opportunity to complete as much as possible whilst still outdoors, by bunching the material between the fists and twisting off small plugs, or by snipping bunches into short sections with secateurs. Alternatively, the use of a cog-drive garden shredder will really come into it’s own here, making short work of comminution, with the advantage that it both chops and crushes leafy material. Only where very fine comminution is required will you have to withdraw to the kitchen for final food-processing or vigorous work on the chopping board.
Agrimony, Agrimonia eupatoria – 1:3 25%, 7-10 days
The whole aerial herb from clean growth is gathered in summer, early in flowering, (Agrimony repeat-flowers, and it’s best to harvest before seeds have set from the earliest flowers). If this is done, new growth will form and it’s usually possible to get two ‘cuts’ from Agrimony in a good summer. The stems are quite fibrous so are best secateured to 3-4 cm sections, or shredded.
Alecost, Tanacetum balsamita – 1:3 45%, 10-14 days
The leaves of Alecost, or Costmary, can be gathered at any time during summer as soon as they have matured to a blueish tinge. Two or even three harvests are possible. It’s best to pluck the leaves by hand one by one, avoiding any that are blemished, of which there’s likely to be many, particularly if growth has become crowded. Flowering tops when present can also be incorporated. Little or no comminution is required. It’s recommended to prune out any fibrous flower stems at the end of the season.
It’s a sign of the tunnel vision of ‘scientific’ herbal medicine that the close relative, Feverfew (Tanacetum parthenium), has attracted so much attention as a remedy for migraines, whilst Alecost, almost completely unresearched, is far more likely to achieve a cure – and is unsurpassed for treating hormonal headaches.
Artichoke, Cynara scolymus – 1:3 25%, 10-14 days
The leaves of the Globe Artichoke can be harvested at any time in the summer, but if you also prize the huge flower-bud itself as a vegetable it’s best to take the leaves just before the globe(s) start to open, for fear of arresting development. Snip the leaves off near to the stem, taking no more than half of them if you want this to remain a robust perennial. The leaves are soft and easy to comminute coarsely.
One can also use the globe itself as medicine (chop it finely and use the same formula as the leaf), or incorporate it with the leaf, as you prefer. The Globe Artichoke should not be confused with the Jerusalem Artichoke, Helianthus tuberosa, used as a root vegetable and entirely unrelated.
Avens, Geum urbanum – 1:3 25%, 10-14 days
Avens is one of the rare remedies where the entire herb is used, roots and all. It’s best taken very early in flower, (May or June). If the roots come up very dirty you may need to separate them from the aerial herb in order to clean them, recombining the two to macerate. Only moderate comminution is required.
Bearberry Arctostaphylos uva-ursi – 1:3 25%, 3 weeks
This evergreen, found mostly in acid soil in the North & Scotland, can be gathered throughout the year, but is at its best in spring just before flowering. Only the leaves are used, which have to be pulled off this wiry little shrub one by one, avoiding blemished ones from old growth, which are likely to be many. No further comminution is required.
Betony, Stachys betonica – 1:3 25%, 10-14 days
Betony is at its best in full flower – in a good year this will happen in June, giving the potential for a second cut in early September. Harvest the whole aerial herb from clean growth. The leaves and stems are soft and easy to comminute.
Birch, Silver, Betula alba – 1:3 25%, 10-14 days
The leaves of the silver birch are harvested as soon as they’ve hardened off in early summer. It may be more manageable to prune off small twiggy branches in order to strip the leaves at ground level. No further comminution is required. (The ‘waste’ twiggy material is great for training peas and other scrambling subjects).
The buds and bark have also been used. Birch Oil is produced by destructive distillation of the bark. One can tap the sap in spring by drilling a deep downwards-sloping hole (about 20mm diameter) in the trunk, inserting a tight-fitting plastic tube and arranging a collecting vessel below. Yielding as much as 20 litres per day, more than 3 days of this punishment may irrevocably damage the tree – and do remember to seal the hole afterwards.
Blessed Thistle, Cnicus benedictus – 1:3 25%, 14 days
Harvest the whole aerial herb from clean growth, in full flower, anywhere between June & August. Don’t worry if a proportion of inflorescences have run to seed. Handle with care. Shred or chop coarsely.
Very confused taxonomy – also known as Holy Thistle, you may also reference this under Carduus benedictus or Carbenia benedictus, the latter being favoured in most old texts and some manufacturers’ lists.
Borage, Borago officinalis – 1:2 30%, 10-14 days
The whole aerial herb of Borage can be used, but the best quality is derived from the flowering tops – if you confine yourself to these the plant won’t be irrevocably damaged and two or three harvests are possible, starting in early summer. Borage is soft and sappy, so easy to reduce to the fine mulch required for a 1:2 – at this strength 30% alcohol is recommended due to the very high water content of the plant. An exceptional tincture will develop a deep turquoise colour.
Broom, Sarothamnus scoparius – 1:3 25%, 2-3 weeks
The flowering tops can harvested at any time except winter, but are said to be most potent in early spring. Shred, or bunch and secateur into 3cm lengths.
Dyer’s Greenweed, Genista tinctora, is both smaller and medicinally somewhat milder. Avoid the Spanish Broom, Spartium junceum, very popular as a garden subject, but toxic. Butcher’s Broom, Ruscus aculeatus, is not related although curiously its roots are used for similar purposes.
Catmint, Nepeta cataria – 1:3 30%, 10-14 days
Catmint, (aka Catnip or Catnep), is harvested in flower in late summer (if the cats have been kind enough to leave any behind for you). Use the whole aerial herb from clean growth, or if you have plenty, just the upper leaves and flowering tops. Coarse comminution will suffice.
The Nepetas are a large family augmented by any number of hybrids & garden cultivars. Many, including the ever-popular N. mussini have been used medicinally, and there is certainly room for further exploration.
Centaury, Erythraea centaurium – 1:3 25%, 2-3 weeks
The beautiful Centaury is a viable if challenging garden biennial, or you may be able to find it in the wild, particularly in well managed dry meadows – if so, take no more than one in fifty so others can enjoy the stunning pink flowers. Centaury, a relative of Gentian, is intensely bitter, so a little goes a long way. Pluck the whole aerial herb from clean growth and simply snip into 3cm sections for tincturing.
Chaste Tree, Vitex agnus-castus – 1:3 45%, 2-3 weeks
We’re all accustomed to using Chasteberries, (or simply ‘Vitex’), the dried black fruits imported from Southern Europe where this large and handsome shrub is indigenous. Contrary to popular opinion, it can easily be grown in the south of the UK – it will need a sheltered, sunny aspect, and some winter protection for the first year or two, but once well established will survive the harshest winters. It may ripen berries by the late autumn after an exceptionally hot summer, but in the UK it accumulates admirable amounts of the active constituents in the leaves, furnishing a more reliable harvest taken in late August. Clinical experience indicates that this is gentler but just as effective as the dried berries.
Choose a hot day late in August. Prune back all but the base 10cms of the new year’s growth. It’s best to do this to the whole shrub even if you can’t use it all, to keep it tidy and to encourage production of straight wands the following year. Strip the leaves downwards and pluck off any flowering tops, discarding the stems. No comminution is required, though a little chopping will make a 1:2 tincture possible.
There are other Vitex species with medicinal uses, including the V. negundro used in Oriental medicine, but have not so far proved successful in the UK.
Chickweed, Stellaria media – 1:3 25%, 7-10 days
Chickweed, the ubiquitous weed, can be harvested at any time of year, although the most likely time to find it both lush and clean is in later spring. Note that Chickweed should be differentiated from Scarlet Pimpernel, which may look similar when the flowers are absent or closed. Use the whole aerial herb, which you are likely to need to pick through carefully. Coarse chopping is sufficient for a 1:3 tincture. Being a very mild subject, you may prefer to food-process it to aim for a 1:1 30% product.
Chickweed is particularly valuable in creams and ointments, incorporating the fresh herb liquidised or juiced, or as a strong infusion.
Cleavers, Galium aparine – 1:2 25%, 7-10 days
Cleaver, Clivers or Goose Grass never needs cultivating due to its prevalence as a scrambling garden and hedgerow weed. The whole aerial herb is used and can be gathered at any time of year except winter, but is at its best (and easiest to handle) before seeds set in late spring. It usually needs to be picked through carefully. Fairly fine chopping and/or food processing will be required to achieve a 1:2 tincture, which is recommended for this fairly bland subject.
Cleavers is easy to juice and is often recommended in this form for serious lymphatic conditions.
Coltsfoot, Tussilago farfara – 1:3 25%, 10-14 days
Coltsfoot is a curiosity as the flowering stems appear as early as February, which will then have died back long before the leaves emerge a month or two later. If you can find sufficient flowers, they are covered in the ‘Flowers’ section, including the possibility of combining them with a later harvest of leaves. To harvest the leaves alone, gather as soon as mature, (usually early May), and comminute coarsely.
Comfrey, Symphytum officinalis – 1:2 25%, 10-14 days
You can harvest the whole aerial herb, or just the leaves – but what’s recommended is that you grow enough Comfrey to provide both fertility for the garden and for medicine as well. You’ll then have enough to use the flowering tops for medicines, maximising allantoin content whilst all but completely avoiding the pyrrolizidine alkaloids that we’ve all been brainwashed into fearing, however irrationally. What’s left can be cut at ground level and used to add to compost, or wilted for a mulch, or better still converted into a liquid feed.
Comfrey usually comes into full flower in late May – snip off the flowering tops with some leaves, (something like the top third of growth). You may be lucky and get a second cut in later summer, but beware, Comfrey often develops mildew and/or rust later in the season. Comfrey is soft and easy to comminute – but watch out for the very high mucilage content clogging shredders or food processors. A 1:2 tincture is easy to achieve but you may want to increase the alcohol content to 30%. An exceptional tincture develops a deep green colour.
The Comfreys constitute a large family with any number of hybrids and cultivars. It’s highly recommended that you ignore them all and stick to good old-fashioned S. officinalis for a high allantoin, low alkaloid, reliable variety. Comfrey root was often preferred in the past for dried-herb tinctures, but shows no discernible advantage in fresh form, and in modern practice is not recommended for internal use. Comfrey is also much used in a variety of external preparations – again, the aerial herb will prove adequate for most purposes with the possible exception of poulticing.
Dandelion, Taraxacum officinalis – 1:2 25%, 2-3 weeks
Dandelion leaves can be harvested at any time from spring to autumn, although they are seldom at their best in dry summer weather. Avoid after a strong downpour when soil-splash is a problem, equally avoid when flowering profusely, as the flowers and flower stems are not wanted and will have to be picked out. Fine comminution is recommended to achieve a 1:2 tincture of this invaluable but bland herb.
See also under Dandelion root. The latex of the flower stems is used externally to treat warts, but the stems and flowers are mildly toxic internally.
Deadnettle, White, Lamium album – 1:2 25%, 14 days
This ubiquitous ‘weed’ of waysides and garden margins is harvested in full flower, any time from April onwards, taking the flowering tops. Fine comminution is both easy and necessary to produce a 1:2 tincture of this bland herb.
There are other ‘Deadnettles’ (i.e. ones that don’t sting) such as Red Deadnettle (L. purpureum), Yellow Archangel (L. galeobdolon) and Woundwort (Stachys sylvatica) that share White Deadnettle’s astringent, wound-healing properties, but the benefits to the female reproductive system are unique to L. album.
Eyebright, Euphrasia officinalis – 1:3 25%, 2-3 weeks
The diminutive Eyebright is a parasite on grass and is most often found on the margins of well-used pathways and ‘rides’ in open country. As it’s not particularly common, harvest only one plant in ten and keep an eye in subsequent years that you’re not causing depletion. The whole aerial herb is gathered in full flower from mid-summer to late autumn – try not to uproot any plants if possible. Being very fibrous, comminution is best achieved by shredding, or secateuring bunches into 3cm sections.
Feverfew, Tanacetum parthenium – 1:3 25%, 10-14days
Feverfew, or Batchelor’s Buttons, should come into full flower by July. It’s easiest to cut the whole herb from clean growth and withdraw to a convenient workplace. Working on one stem at a time, strip off the leaves and flowers, discarding the stems. No further comminution is required.
Avoid variegated Feverfew or any other garden cultivars. Note that there are rare cases of contact dermatitis from handling Feverfew – if in doubt, do a 24 hour patch test first, or wear gloves anyway.
Figwort, Scrophularia nodosa – 1:3 25%, 14 days
Cut the whole aerial herb from clean growth during flowering in early summer – but be vigilant, the flowers are insignificant and quickly turn to seed. Comminute coarsely – simply secateuring bunches into 3-4cm sections will suffice.
Ginkgo leaf, Ginkgo biloba – 1:3 25%, 3 weeks
Unusually, the leaves of the beautiful Maidenhair Tree are at their most potent as they yellow off in early autumn. Exactly when to go for it is a tricky calculation – Murphy’s Law will arrange high winds the night before optimum condition is reached, resulting in a bare tree and your valuable crop scattered over several neighbours’ lawns. Presuming you’ve got it right, some ladder-work will be necessary – the leaves will strip off easily, in fact too easily, so you may want to try the precarious ploy of holding a large bowl or similar beneath the area you’re working on, (no problem if you happen to have three hands). Alternatively, lay tarpaulins on the ground and shake or knock the leaves off with a stick. No further action is necessary for a 1:3 tincture if the leaves are layered flat in the menstruum – comminute finely if you want a 1:2 of this relatively bland subject.
Everybody should have a Ginkgo tree! Purchased young from a nursery, they grow on very quickly and are impervious to pollution, (some say they help to clean polluted air). You will almost certainly be supplied with a male plant as the females produce seeds that, although used as a medicine in the Orient, cause an evil-smelling mess when they fall.
Goat’s Rue, Galega officinalis – 1:3 25%, 14 days
You can cut the whole aerial herb when it flowers in mid-summer, but for the best quality take only the upper half. Comminution is easy – you may opt to arrive at a fine mulch and thence a 1:2 tincture of this fairly weak herb.
Golden Rod, Solidago virgaurea – 1:3 25%, 2-3 weeks
The European Golden Rod is harvested in full flower in late summer, taking the whole aerial herb from clean growth. The stems are quite fibrous – run through a garden shredder or bunch and secateur into 3cm sections.
The Canadian Golden Rod, S. candensis is used for more or less the same purposes in N. America. It has become such a popular garden subject in the UK that it’s escaped into the wild, where it can prove quite invasive. Nevertheless it’s medicinally inferior in our climate – use it if you have no choice, but for the best quality go for our own indigenous Golden Rod, slower growing and a smaller plant, but well worth the effort.
Ground Ivy, Glechoma hederacea – 1:2 30%, 10-14 days
Ground Ivy (not an Ivy at all, but a member of the Nepeta family) is common enough in open woodland, but this pretty harbinger of spring is worthy of any garden – although it can prove quite invasive. Harvest as soon as it flowers, any time from March in a warm year. The leaves and flowers are what’s wanted, but this is a creeping, many-rooted and densely matted subject – inevitably you will find it comes away with a few roots, not to mention winter debris and other species that it’s become entangled with, so painstaking picking through may be necessary. If the result is indeed just leaves and flowers, little or no further comminution will be required to achieve the recommended 1:2 tincture of this bland but invaluable herb.
Gypsywort, Lycopus europaeus – 1:3 25%, 10-14 days
Harvest in full flower in mid-summer, using the whole aerial herb from clean growth. Shred, or bunch and secateur into 4cm lengths.
If introducing this to your garden, be warned that it can be as invasive as its cousins, the Mints. The American L. virginicus is said to be stronger, but not in the UK, where it lacks vigour.
Heartsease, Viola tricolor – 1:2 25%, 10-14 days
You’ll be lucky to find Heartsease in the wild, but it’s an easy garden annual, and if a few are left to self-seed may become naturalised, (or may not – it either seems to do spectacularly well, or vanishes). Pick the whole aerial herb in full flower, any time between April and the first frosts of autumn. Comminution to a fine mulch is easy.
Horehound, White, Marrubium vulgare – 1:3 25%, 2-3 weeks
White horehound usually comes into full flower in June. Use the flowering tops, being careful to cut no more than the top half of the new season’s growth, otherwise the stems concerned or even the whole plant will die. A second harvest may be possible in early autumn. Fine comminution will be required to produce a 1:3 tincture or stronger.
Horehound is often preferred as a syrup, particularly for children, and was in times gone by the principle ingredient of the famous ‘Cough Candy’, although it’s probably absent in modern confectionary. Black Horehound, Ballota nigra, is vaguely similar in appearance but radically different in both aroma and indications. It can be treated in all respects the same for tincturing.
Hyssop, Hyssopus officinalis – 1:3 45%, 14 days
Hyssop flowers throughout the summer. Use the flowering tops, taking care to cut no more than the top two-thirds of the new year’s growth, for fear of damaging or killing the plant. Pass through a garden shredder, or bunch and secateur into 3-4cm sections.
Hyssop, popular as a long-lasting perennial garden subject, is often offered in pink- or white-flowering varieties. Stick to the original and more robust blue flowering variety.
Lady’s Mantle, Alchemilla vulgaris – 1:3 25% 2-3 weeks
Lady’s Mantle, the much loved front-of-border perennial, comes into flower in June. If harvested then, a second cut may be available in late summer. Cut the whole aerial herb from clean growth, picking through carefully to discard any ‘browned off’ leaves. Don’t worry if some ‘dew’ remains in the leaf cups – this is actually part of the plant’s own transpiration process and in energetic terms has to be considered a bonus. Lady’s Mantle is easy to comminute coarsely – this is an ideal opportunity to try the ‘hands only’ approach and twist fistfuls of the gathered herb into plugs.
There are hundreds of Alchemillas, all of which are likely to be therapeutically viable, though few adapt well to an enforced change of habitat. The variety most popular in English gardens (pretty, vigorous and unfussy) is A. Mollis, which is hard to distinguish from A. vulgaris and serves every bit as well.
Lemon Balm, Melissa officinalis – 1:3 45%, 4-8 hours
Lemon Balm comes into flower as early as June, but do wait to harvest this Mediterranean subject after midday on a really hot day. A second, late-summer cut is possible but likely to prove inferior. The leaves and flowering tops are used. Cut the whole aerial herb from clean growth. Working on one stem at a time, strip the leaves off downwards and pluck off the flowering top, discarding the stem. Very little further comminution is required. Work quickly throughout to capture as much as possible of the extremely fugitive essential oil.
The recommendation to macerate for only 4-8 hours is not a misprint – the essential oil is held at the leaf’s surface, so extracts very quickly. Longer maceration both encourages leaching of the all-important essential oil whilst the tincture becomes ‘stewed’ with unwanted tannins. Given the short maceration time, you may opt to repeat-macerate for a 1:2 tincture or stronger.
There are commercial cultivars available, often to provide variegation or alter the aroma (e.g., to ‘lime’), that should be avoided. There are also ‘commercial’ varieties selectively bred to increase the essential oil content.
Lettuce, Wild, Lactuca virosa – 1:2 30%, 10-14 days
Wild lettuce can be ‘forced on’ from a spring sowing to flower by late summer, but it’s best to treat it as a biennial, sowing in autumn and harvesting in mid-summer. Although the flowering tops are highly desirable, the priority is to harvest during a patch of hot, dry weather, when the all-important latex will run copiously from a cut stem. Take the whole aerial herb from clean growth. Fine comminution is both easy and necessary to produce a 1:2 result, recommended, as this is not a particularly strong remedy.
Although cultivated lettuces (from L. Sativa) do produce some latex, especially if left to run to seed, the history of breeding them as a salad vegetable is mostly to do with substituting sweetness for bitterness, the latter being caused primarily by the bitter alkaloid – the main medicinal constituent of the plant. There are other wild lettuces, notably the Prickly Lettuce, Lactuca scariola, that are therapeutically viable but less potent.