Herb growing Ireland – How to grow herbs – Herb growing workshop – Gretas Herbs Annascaul, Dingle

Herb Questions and Answers Published January 15, 2012

Filed under: Published Articles — gretasherbs @ 4:22 pm

I am starting a new article in    West Kerry Live Magazine from the end of this month onwards. Readers need to email their questions to me at gretasherbs@yahoo.com!  A monthly draw will occur for all those whose questions get published and the prize is a €15 herb voucher! Good Luck!

West Kerry Live 2nd  February 2012

What are the best and most common healing herbs to grow in a greenhouse?

Frank Buckley Castlegregory

I am not a Herbalist so can not recommend any herbs for ingestion. However I believe that scent has a calming, therapeutic quality so try growing Lemon Verbena in your green-house, it has the most powerful scent of all and reaches about6 footin height! Other herbs which have an intense aroma and will enjoy the heat are Lavender, Lemon-Balm, Basil and Scented Geraniums. You can also try growing a variety of Citrus fruits from pips, they won’t produce fruit but will give your green-house a Mediterranean atmosphere. They make beautiful scented pot plants but are slow-growing initially so have patience!

I am a Felter and wish to grow some herbs that will enable me to dye Merino wool?  I would appreciate some advice in this area and would be very grateful for any information.

 Anne Hennessy  Tipperary

All plants will result in some colouring. You’ll find a wide range of  herb plants that will produce colors in yellow, yellow-brown and grey-brown tones. Deeper golds, russets and reds are a bit harder to come by and blue and purple are down-right challenging. A great deal of plant material is necessary to achieve an intense color. As you probably already know the addition of various mordants (an element which aids the dye to fix) dictates the resultant colour. For example Taraxacum officinale (Dandelion) root turns wool magenta when the mordant alum is used, however, the use of tin and vinegar results in purple wool, and yellow is the color when no mordant is added. The flowers also yield a yellow dye. Calendula officinalis (old English marigold) infusion yields a pale, yellow dye even though the flowers are orange! Hypericum perforatum (St John’s Wort) gives a red dye when using a tin/vinegar mordant. I would advise you to experiment by also gathering material from other gardens. Tree foliage such as Eucalyptus and Alder may also be used. The varieties I have mentioned in this article are all very easy to grow and most of them are perennial, but do not limit yourself, try everything!

Brown: comfrey, fennel, geranium Blue: Inula helenium (Elecampane)
Pink:  chicory,  Green: Nettle, angelica, foxglove, marjoram, rosemary, tansy.
Grey: poplar, raspberry Red: sweet woodruff, hops Yellow: Solidago species (Golden Rod)

I find it difficult to grow Basil any tips? What are the best 3 or 4 herbs to grow if you only have room for a few pots?

Ann Hartnett, Annascaul

Sweet Basil (large leaved) is the one most commonly grown. It is a very tricky herb to cultivate in our unpredictable climate. It desires a hot, dry environment so full sun is essential. I would advise keeping one pot inside on a sunny window-sill and one outside. Always water it mid-day avoiding the foliage, never during late evening as this can give it a chill. If space is limited to pot culture grow the most versatile, compact, varieties such as Coriander, Parsley, Oregano, Chives and Mint. Larger pots will contain Rosemary, Bay and French Tarragon. When potting up always mix some garden soil with the compost and liquid feed 10-14 days with an organic brand.

Does Parsley do better in full sun or shade?

Maeve Harnett Annascaul

From my experience I find Parsley does best in a rich, moist soil in a position that gets sun for half of the day. It will also thrive in full sun provided the soil is kept well watered. It has a habit of going to seed quickly on poor, dry soils.

I was given a Rosemary plant for Christmas, how do I care for it and can I plant it outside in the ground?

Derek Hunt Annascaul

If the plant you have is small, grow it on outside in a pot for another year or two. Otherwise plant it in the ground late March to early April. It loves a sunny, sheltered position, remember to give it ample space as it grows 5-6ft in height. It is an evergreen shrub so it is available to add delicious flavour to your lamb etc all year round! If the soil is heavy add some silver sand (can be purchased in Garden centre). Top-dress it annually in Springtime with compost and a sprinkle of organic fertilizer and liquid feed it weekly throughout the growing season. Little pruning is required just remove any dead or broken branches  as they develop throughout the season.

What are the main guidelines for planting culinary herbs?

Siobhan Guilfoyle, Annascaul

The main planting season is March to end June. Herbs should be grouped depending on their site and soil requirements ie Thymes need full sun in a light sandy soil and Mints like a damp soil in semi-shade. Read individual labels and allow adequate growing space as some varieties such as Lovage can reach up to6 ftin height. Add a handful of organic soil enricher (shop bought or home-made compost) and a sprinkle of organic fertilizer when planting. If growing in containers ensure to mix soil with compost etc this gives a longer lasting compound. Good Luck!

What is the best way to grow Nigella flowers and Fenugreek? Is it possible to harvest the seed?

Rachel Holstead, Ventry

Nigella sativa (black cumin) is the main variety used for seed harvesting however Nigella damascene with it’s pretty ‘Love in a Mist’ flowers has black seeds which are  also edible! This is an easy annual which freely flowers in a good soil in a sunny position, sow broad cast so it germinates en masse. Fenugreek (Trigonella foenum) described in the catalogue as an easy herb to grow I found much trickier.  I have tried growing it once with little success, it definitely requires a hotter, sunnier climate than ours! It is a pretty plant with clover, type leaves (young leaves are edible) and has scented pea like flowers. The seed which are produced in pods are used a lot in Indian cuisine. Whole seeds are pickled  and are also ground to make a curry powder. I would suggest you give it a grow! You may have more luck than me. I have never harvested seed from either of these plants. However, I do know from collecting seed from other plants that you need to harvest when seed has properly, ripened on a calm, dry day.

What herb would be good to help me sleep and how should I take it?

Monika Maroszova, Castlegregory

I am not a Herbalist however Valerian is particularly good and you can get it in the health food store. Chamomile tea is also a pleasant night cap. Other remedies include Lavender or Hop oil baths before bed. Also placing a sachet of lavender under your pillow should help send you into blissful sleep!

 March 2012

Why does my Rosemary plant get so woody after a short time? How toxic is the oil?

Joan Greene, Inch Hotel

This question arises a lot. Rosemary (Rosmarinus officinalis) is slow growing so it is important to encourage rich, green growth from the base. Ensure to purchase a bushy plant and top dress annually in Spring with a mix of organic soil enricher and granular fertilizer. Also regularly remove dead, spindly stems. It should then grow to become a full bodied specimen. Mature plants that have grown excessively woody may be hard pruned in April however there is a risk of losing the plant. Otherwise the only option is to replace it. The second part of your question should be directed at an Aromatherapist. I would not consider Rosemary oil toxic except like most oils it needs to be mixed with a base oil such as almond to reduce it’s concentration and to prevent a skin reaction.

What are the best Herbs to grow in pots?

Pauline Hunt, Annascaul.

Small herbs such as Golden oregano, Chives, Thyme varieties and Parsley are ideal planted in groups. Larger varieties such as Lovage, Rosemary and Bay may be planted individually and of course Mint should also be confined as it is highly invasive! Any type of container can be used but terracotta is definitely the most suitable and the most aesthetic.

Can you give me some beginner’s tips on growing lettuce and salad herbs in containers?

Ursula O Connell, Dingle

You can commence sowing now in containers i.e. fish-boxes using potting compost mixed with some garden soil and a handful of organic fertilizer! Adding a little processed manure or soil enricher (bagged product) gives the mix an extra charge of nutrients promoting lush growth! The easiest Lettuces are the cut and come varieties such as Salad bowl green or red leaved. Selection packets of salad greens can also be acquired but are very popular so immediate purchase is necessary! An easier option is to buy ready to plant Lettuce and Salad Herbs like Parsley, Mizuna, Mustard Greens and Rocket. The Wild Rocket is wonderful as it is a hardy perennial so will flourish through a mild winter. The ordinary Rocket is an annual which disappears quickly so sowing in succession is vital. If you are growing from seed sow every 2 weeks, a little at a time, most people over sow! Regular watering and liquid feeding is all that is required. Remove any flower buds that attempt to develop on the Salad Herbs. Watch out for slug attacks at all times ensuring to scatter pellets (preferably organic) on the surface after sowing or planting. Harvesting occurs sooner than one imagines usually 4 to six weeks from seed and from plants almost instantly.

Does Basil need to be grown inside all year round? I have planted flat leaf Parsley and Dill and they are thriving but the Basil hasn’t grown and it appears there is a fungal growth across the top layer of the planting pot.

Gareth O Donnell, Annascaul

Basil is extremely difficult to cultivate, it germinates easily from seed sown March to June but forget about it in winter. It will only reach maturity in the height of a really hot, sunny summer. I recommend placing one pot outside and retain one inside on a windowsill. The fungus you describe often occurs due to over watering and is more prevalent in dreary, sunless conditions. Your Parsley and Dill should be moved outside once weather improves.

What is the best manure to put on Rhubarb?

Martin Sayers, Annascaul

Rhubarb requires a rich, moist soil so regular feeding is important. Spreading manure of any kind i.e. horse, cow etc around the base of the plants is extremely beneficial however it must be well rotted or it may scorch or even kill the plants. Autumn is the ideal time to do this practice of mulching as it smothers weeds and lends some protection to the roots. It also creates a type of hot bed so the Rhubarb may emerge earlier and stronger! You can however mulch now in spring and then in about 6 weeks apply a scattering of fertilizer.

April 2012

How do I care for my Jasmine plant and when should I feed it? The base of the plant is quite bare showing no new shoots.

Trica O’ Sullivan Annascaul

There are many varieties of Jasmine so I am assuming that you are inquiring about either Jasminum polyanthum (Indoor) or Jasminum officinale (outdoor). Both species have white scented flowers however J. polyanthum has a far superior fragrance. There are numerous other outdoor varieties which require similar care to J officinale, that being a sunny, sheltered wall and a rich, well-drained soil. Normally pruning is done after flowering on both these species and mainly consists of removing weak shoots. However in this case you may now prune back a majority but not all weak shoots to ground level in order to revitalize the plant and encourage it to sprout from the base. The flower production may be less this year but overall appearance and blossom will improve in subsequent years. Plants should be top dressed with organic soil enricher and granular fertilizer in April and again around mid June. Liquid feed weekly once temperature increases with last application ceasing the end of August. Jasminum polyanthum can only be grown inside on a sunny windowsill or conservatory. Its scent is breath taking! It is usually sold in full bloom, trained to a hoop supported in a tiny pot. Many plants are forced into flower in this manner by restricting root development, another example is Azalea. It is important when re-potting to just increase pot size by 1 or 2  otherwise the plant will explode in an excess of leaves with little blossom. Under these imprisoned conditions J polyanthum must be lavished with liquid feed. When in flower keep moist at all times but reduce watering in winter. As it matures remove the hoop and train along an indoor trellis or up bamboo canes. It can grow over 20ft in length and is a magnificent conservatory plant.

I have a side garden that gets around 4 to 5 hours of sun, is it suitable for Fennel?

Pat Moriarty,Tralee

Fennel is a herbaceous perennial which means it dies down completely in winter so several daily hours’ sunlight in spring and summer is adequate. The bronze variety forms a pleasant contrast to the green. Both are easy to grow but tend to re-seed a lot so remove flower heads before they set seeds otherwise your side garden may become invaded!

How do I keep Spinach growing so there is a long supply and how does one prevent it going to seed?

Celia O’Brien Inch

Spinach is very prolific, yielding several seasons’ harvest. To ensure a continuous supply it requires a rich, moist soil. Remove any flower shoots which tend to occur in dry weather. To aid moisture retention, mulch several times in the growing season with organic compost and liquid feed regularly. I am presently harvesting Swiss Chard (type of Spinach) from last year’s crop!

April 2012

How do I grow Coriander?

Cheryl McLeod, Annascaul

Coriander is a much loved herb which can be grown successfully from seed or else purchased as plants from April to June. It does like a sunny location but is a lot hardier than Basil. I suggest you plant some outside and retain 1 or 2 for a sunny windowsill inside. The varieties ‘Cliantro’ or ‘Slowbolt’ are an ideal choice as they are slower to go to seed than other varieties, especially in dry, hot weather. Sowing seed a little every 2 weeks should provide ample cutting throughout the season.  Keep it well watered and liquid feed weekly to encourage plenty of foliage. The seeds of Coriander may also be collected and crushed to make a spice at the end of summer.


Are there many different varieties of mint i.e. lemon which grow easily in our climate?

Arty Clifford, Dingle

There are many fantastic varieties of mint which can be easily grown here in Kerry, particularly because, unlike Thymes, they can tolerate excessively wet conditions. Grow them in pots as most are highly invasive. Try Lemon, Peppermint, Eau de Cologne, Lime,

Spearmint, Applemint and most exciting of all Chocolate Peppermint. The only one I tend to find less hardy is Gingermint, it is very ornamental with gold striped leaves. A new addition is Indian mint. This is a trailing variety which combines scent to hanging baskets and tubs!


My Garlic tends to get rust like spots on the leaves half way through the growing season and the bulbs remain small but edible. What is causing this?

Brita Wilkins, Baile an Trasna, Ventry

I have never had this problem with Garlic so I am guessing a little on this one! I imagine it is mainly due to the dreadful wet summers in recent years. So diligently improving soil drainage may help. Ensure to add sufficient sand (horticultural sand may be purchased in Garden Centres) and grow on drills or raised beds. If you can, use a cloche to give some cover from excessive rain mid-summer. Rust, like blight is a fungal disease which is  infectious, so foliage must be burned as it can spread to other crops, like wise in reverse your Garlic may be getting infected from other plants nearby which may be carrying rust disease so check around. Excessive leaf growth caused by too much nitrogen can promote the disease so go easy on fertilizers. This year just add potash to try to balance out the soil composition. If the bulbs remain undamaged then the dreaded white rot is not the problem, if this was the case I would advise you not to grow Garlic in that area of soil for 8 years!

May 2012

How do I grow Sage?

Patrica McCleod, Annascaul

Sage is a perennial herb which means it should last for several years. Unfortunately like Thyme it has a tendency to rot during our constant rainy weather! Generously incorporate horticultural sand into the soil where it is planted to aid drainage. Lightly clip dead or straggly stems in April and top dress with organic compost and a granular fertilizer to encourage fresh growth. Salvia officinalis (common Sage) is the most vigorous variety. There are beautiful, decorative gold, purple and tricolor varieties which may be less hardy but are very eye-catching and may also be used in cooking.

What is the main pest which attacks carrots?

Anthony Leo Dempsey, Annascaul

The Carrot Root Fly is the carrot grower’s nightmare! It is a small black fly which lays its eggs at the base of the carrots during the growing season of April to August. These hatch out to become rampant, creamy white maggots which tunnel through the carrots, decimating the crop Ugh! There are two preventative methods which should be used to ward off this destructive pest. Firstly the fly is attracted to the carrot aroma especially during thinning so try to minimize this by quickly discarding and disposing of all carrot  thinnings. Even better, try and avoid thinning by sowing seed lightly and carefully. Inter-planting or companion planting with onions, garlic and pot marigold (Calendula) also helps as does the planting nearby of heavy scented herbs such as Rosemary or Sage. The second effort involves the creation of a barrier so the fly cannot land to lay it’s eggs. The use of fleece in recent years has proved successful, making sure to imbed the edges so the fly can’t sneak in. The construction of a 6o cm high polythene barrier around the crop can also prevent access as this pest is a low flyer. The scientists have been endeavoring to breed a carrot variety resistant to this pest for almost two decades. They have managed to reduce the chemical within the carrot which the larvae (maggot) requires for survival. In recent trials the variety Flyaway proved most successful other varieties displaying some resistance include Flyaway and Health Master.

My Rosemary is growing upwards alarmingly, but remains quite sparse. Should I be cutting it back and if so how and how often?”

Ann O’ReganLimerick

Rosemary does not tolerate severe pruning so prune lightly anytime during the growing season but never in winter. Remove dead or spindly branches and trim to encourage bushiness. Light, regular pruning will ensure a good shape. It prefers a sandy soil if your soil is very rich it will have a tendency to sprout soft growth, so refrain from over feeding this year. A light application of an organic granular fertilizer is adequate this again should be added only in the growing season.

Which herbs are best for honeybees?

Marie Charland, Ballydavid

There is a wide selection to choose from so I am limiting it to free-flowering varieties which flourish in our climate. Obviously the more flowers the more nectar and pollen for hungry bees! Many self seeding annuals such as Borage and Calendula will provide blossom en masse for many years, once you are not averse to a little wildness in your garden as they will pop up like weeds! Rosemary (R. officinalis) is another excellent choice as it has a long flowering season and grows into a substantial6’shrub.St. John’sWort (Hypericum perforatum) is also worth a go as it spreads quickly and reseeds everywhere. Honeybees love Thymes, Lavender, Sage and Hyssop, these pleasant aromatic herbs need a lot of sunshine and a very well-drained, sandy soil otherwise you can lose them in winter. Much easier subjects are Chives, Fennel, Lemon Balm, Oregano and Mint especially Apple mint. All these are perennial and spread rapidly once given a  sheltered, sunny position which is also important for our bees. According to my herb reference book ‘bees ignore plants within a radius of approximately 15m from the hive as this area may be contaminated by the bees’ own cleansing flights’. Bee keepers will no doubt understand this concept. I recommend planting in groups of 5 or 7, to add extra interest and colour include Poppies and ornamental Nettles (Lamiums) these are non-stinging varieties. Bergamot (Monarda didyma) commonly known as bee balm is a very pretty plant, it does attract honeybees but they unlike bumble bees cannot reach the nectar due to the narrow tubular flower structure! Comfrey, Golden rod (Solidago) and Sunflowers are also excellent and a joy to look at. Apart from the herb plant kingdom there are lots of other bee-attractors especially native plants such as Fuchsia and Heather.  If you are blessed like I with a natural hedgerow of our precious flora –what a beautiful back-drop this would make for your bee garden!


I purchased herb plants several weeks ago, can I plant them now?

Iain, Slea Head

All plants need a hardening off period before planting out into the ground or into bigger pots. If they have already been outside in a Garden Centre or Nursery then continue to leave them outside for a week, or longer if temperatures are cool. Plants purchased from indoor stores will not have been hardened off . These will need a lot more care by placing outside daily but bringing in at night until they are acclimatized, then leave them out completely again for one week before transplanting. Many such as Basil or Coriander are grown out of season in heated conditions and will not adapt to outside temperatures unless it is the height of summer. Retain them on your windowsill and harvest for as long as possible.

June 2012

I have a small flea-like fly in my compost eating my baby spinach plants; what can I do? Vikki Louise, Munster Trader

My guess is that your Spinach is being eaten by the flea beetle. This treacherous, shiny insect hops about quickly, leaving round holes in the leaves. Seedlings growing in dry compost are especially vulnerable so keep everything well watered as these pests seem to like dry conditions. I used to apply Derris dust which was an organic derivative from a plant root however I see it is now banned. There probably is some form of chemical control of which I am not aware. The other prevention is companion planting, they love radish and will be drawn to those as it is only the leaves they attack and you can still consume the radish! Inter planting with strong scented herbs like garlic, chamomile and marigold may help. Other methods involve sticky tape traps and home-made organic mixes to deter them but you will need to contact an organic grower for advice on these. Another tip that may reduce attack is to delay sowing until later in the season. The eggs develop over winter and hatch out in late spring. Depriving the first emerging generation of food may starve them out. By observing and studying the lifecycle of non-beneficial insects we gain an understanding of how to naturally reduce their population without completely eliminating that species. This is how we achieve a harmonious balance in the garden.  I rarely encounter flea beetle attacks and when I do it is usually brief.

How do I control club-root on Cabbages as I can no longer obtain Calomel?

Mike Devine

This is a serious soil-borne disease which attacks Brassicas (members of Cabbage family), stunting growth and completely distorting the roots: hence its name! Yes Calomel was a powder we once mixed with a mud paste into which we dipped the cabbage roots to prevent the disease. Like so many other chemicals it has now been banned. It contained mercury mineral and was once used in a variety of fungicides. Research has shown in recent years that it does not break down safely and is a danger to human and wildlife. There are no doubt replacement chemicals such as Borax which control the disease. Club-root spores can reside in the soil for 20 years so it becomes an on-going problem. The application of ground limestone every few years is   recommended to raise the pH as this fungal disease thrives in acidic soils. Planting in raised beds to enhance drainage should also help as the fungus loves damp conditions. Try specific Cabbage varieties such as Kilaxy which have been bred to resist this disease. You will however have to raise these from seed as conventional plant varieties appear to be those mainly on offer. Hygiene is also crucial so never leave infected plants laying about burn them! I don’t grow Brassicas anymore as I find Swiss chard, Burly and Red Russian Kale far easier greens to cultivate. Caterpillars are also a dreadful pest on all members of the cabbage family. I prefer trouble free vegetables.

July 2012

This is my final garden article of the season. I wish to thank my contributors and readers and hope the question and answer section has cultivated an interest in herb growing. Some of your questions were challenging, demanding  research  but I always enjoy gaining further knowledge about such a vast subject.

The season has been extremely erratic with fluctuating temperatures amid endless rainfall. Even though it is now mid July it feels more like Spring than summer. The hardy perennial herbs such as Oregano and Fennel have grown with remarkable vigour. The colourful delights of the ornamentals such as Lupins and Oriental poppies have defiantly blossomed; however, sadly their glory was short lived! The adverse conditions affected many salad herbs like Mizuna & Red Mustard Greens prompting them to bolt prematurely. Often they appeared unable to discern whether they were at the beginning or end of their growing season.  Top heavy blooms of self-seeding Borage  were lacerated and toppled by wind. The only way to combat the mess is to prune back and liquid feed to urge a surge of new buds. Staking of course helps, but I like many, never seem to get there on time. Dead heading Pansies and Calendula after rain is an essential and continuous task. The war against slugs continues and I have yet to acquire copper wire to encircle varieties they find irresistible, a method I am told is highly effective. My recent addition of a pond will hopefully attract a massive population of hungry frogs for next year’s generation of Slugs. Normally I would advise against planting mid summer, however as the soil is moist, plants will transplant easily and there are presently plenty of bargains! Sowing fast growing vegetables like Lettuce Salad Bowl, Rocket, Radish and Spinach may continue successfully and will provide a late harvest. We may well end up with an Indian Summer, a gardener always lives in hope!


Herb Garden Classes

Filed under: Garden Classes 2019-2020 — gretasherbs @ 3:33 pm
I have given a Herb Workshop at the Dingle Food Festival last September 2011. It has become a wonderful annual event!