In your herb garden in April 2012

Contents

• Flavour from the garden this month
• Herbs to propagate
• Pest and Disease watch

Things to do in the herb garden in April

• Plant out hardy herbs, such as comfrey, sage and yarrow, that have been growing in pots over winter. Harden them off in a cold frame before moving them into final positions.
• 
  
  
  Trim woody stems down to
  fresh growth
  Sow seeds outside. See below for a list of herbs suitable for sowing outside
• Sow basil seeds in warmth. A sunny windowsill is fine. You’ll produce sturdy seedlings that will flavour your favourite dishes all summer and well into the autumn.  Basil can be planted outside once all danger of frost has past, but plants grown inside will have larger, lusher leaves.
• Thin out any March seed sowings, allowing strong plants to develop.
• Hard prune shrubby herbs such as cotton lavender (Santolina), bay and rue. This will encourage vigorous new growth and side-shoots.
• Trim old stems from marjoram and savoury, if not already done.
• Prune lavender into shape, taking care not to cut into the old wood. Offcuts can be used as softwood cuttings. Old, woody plants are best grubbed up as they will never recover.  Start again with fresh, new plants.. See below for instructions on taking softwood cuttings
• Divide clumps of herbs that have become too large. See below for instructions on propagation by division
• Plants, such as bay, that are difficult to propagate otherwise, can be layered now. See below for layering instructions
• Hoe and remove weeds as they appear and never let them seed. Chickweed can produce 2000 seeds per plant per season! See the Organic Weed Control for information about identifying weeds.
• Refresh herbs growing in pots.
  • Scrape off the top 5cm/2” potting compost.
  • Replace with sieved garden compost, or fresh potting compost mixed 50/50 with well-rotted manure.
  • Water in well
  • Top with a layer of horticultural grit to retain moisture. It also looks neat.

Flavour from the garden this month

• Caraway (Carum carvi)
  Young leaves have an aniseed flavour and can be added to salads and soups. Roasted seeds can be used in sweet and savoury dishes, though use sparingly as they have a strong flavour. The plants are biennial, which means that they produce seed in their second summer, then die.
Caraway seeds make an excellent breath freshener.
• 
  Lovage – needs plenty of room.
  Lovage (Levisticum officinale)
  Lovage makes a large clump, up to 2m tall. Fresh, young leaves have a celery-like flavour and are great in salads. Crushed seeds can be added to breads and pastries or sprinkled onto mashed potato.
• Chervil (Anthriscus sylvestris)
  The leaves have a delicate flavour, similar to that of parsley though with a hint of aniseed. Use generously in salads, sauces, soups, and with chicken and fish dishes.
  Organic chervil seed is available from the Organic Gardening Catalogue.
• Lemon Thyme (Thymus x citriodorus)
  Leaves have a strong lemon scent and should be used quite sparingly. Ideal with fish and chicken.
• Marjoram (Oreganum vulgare or O. marjorana)
  Fresh young leaves will be growing vigorously this month. This is a strongly flavoured herb that goes well with rich Italian recipes. Use sparingly in salads.
• French Tarragon (Artemisia dracunculus)
  Main ingredient of sauce Béarnaise. Its flavour compliments many dishes including chicken and fish, and it is often used in salad dressings. Beware of any seeds labelled as ‘French Tarragon’ as this variety does not come true from seed and must be propagated from cuttings.
  French tarragon has a superior flavour to Russian tarragon, although the latter is more hardy.

Herbs to propagate in April

Seed sowing outside

• 
  Borage
  
  
  Lady's mantle
• Borage, (Borago officinalis) Annual
  Sow direct in prepared ground in shallow drills 15-30cm, (1-2ft) apart. Borage prefers well -drained soil and full sun. Seeds can also be sown in pots and pricked out into position, but be careful; it does not like to be transplanted.
The pretty blue or white flowers can be added to salads as well as summer cocktails, providing a cucumber like flavour.
• Fennel, , (Foeniculum Vulgare) perennial
  Sow seed under cover in April, and outside in May. If you have fennel plants growing in the garden already, you may find lots of self-sown seedlings that can be potted up. .
  
• Lady's mantle, (Alchemilla mollis) Perennial
  Sow seed in a prepared seedbed in normal garden soil, or in seed trays with a general seed sowing compost. Germination can be erratic. The young leaves can be added to salads and the taste is mild and bitter.
  
  Regularly remove spent flowers or this herb will self seed quite readily and become a weed!
• Lemon balm, (Melissa offiinalis)
  Sow in seed trays of well-drained compost. Prefers a sunny sheltered position in moist rich soil. Variegated and golden forms cannot be propagated from seed.
The leaves make a delicious and soporific tea and can be added raw to salads and yoghurts for tasty salad dressings
• 
  Pot Marigolds will grow
  in most soils
• Pot Marigold, (Calendula officinalis) Annual
  Sow in situ in an area of full sun. Will grow in most soils, preferring loamy soil. Flowers are edible and make a bright addition to a salad, or use the petals in cooking to colour rice. Protect from slugs, as seedlings are very vulnerable to attack. Don’t rely on just one method. Check out the wide range of slug and snail controls available from The Organic Gardening Catalogue.
Organic pot marigold seed is available from the Organic Gardening Catalogue.
• Sweet marjoram, (Origanum marjorana) Annual
  Sow seed in pots or trays April - May. Seed is very fine, so try sowing with small amount of silver sand. Leave uncovered. When large enough to handle, pot on or plant out in a warm, sunny area with medium rich soil, after all risk of frost has passed.
Organic sweet marjoram seed is available from the Organic Gardening Catalogue.
• 
  Sage in flower
• Nasturtium, (Tropaeolum sp.)
  Sow direct or in pots and transplant to prepared site after last frost. If growing for flowers, place in nutrient deficient soil, if growing for spicy leaves, grow in rich soil. The flowers are edible and a colourful addition to summer salads.
Leaves, seeds and flowers can be eaten and have a spicy, mustard like flavour
• Sage, (Salvia officinalis)
  Sow in pots or trays with temperature of 15-21ºC. Plant out in the autumn in light, well drained soil. Place in sunny spot.
Sage grows well in containers


• 
  Feverfew
• Feverfew (Tanacetum parthenium)
  Sow the tiny seed in pots or trays. Fill trays as normal then mix seeds with a couple of handfuls of sand or sieved potting compost. Scatter this mixture on the surface of the prepared trays. Water from below. Germination should be rapid. Plant out as soon as plants are large enough to handle. A hardy perennial, it can be added to salads although it is rather bitter.

  Organic feverfew seed is available from The Organic Gardening Catalogue.

Taking softwood cuttings

Herbs can be propagated in many ways. Taking cuttings is very popular - particularly with variegated varieties. Here's how:

• Remove young, non-flowering shoots and, using a clean, sharp knife, remove the growing tips.
• Remove the lower leaves, leaving just a few leaves at the top of the cutting. Cut the stem just below a leaf node.
• Use a dibber or pencil to insert the cuttings into modules or pots of free draining compost.

This method can be used to propagate:

• lavender (Lavandula spp.)
• lemon balms (Melissa spp.)
• catnip (Nepeta spp.)
• southernwood (Artemisia abrotanum)
• wormwood (Artemisia absinthium)
• sages (Salvia spp.)
• lemon verbena (Aloysia triphylla)
• calamint (Calamintha spp.)
• wall germander (Teucrium x lucidrys)
• wood sage (Teucrium scordonia)
• rosemary (Rosmarinus officinalis)

Propagation by division

Established herbs can be lifted and divided, not only to produce more plants, but also to prevent them becoming straggly and unhealthy.

• Dig up the plant and shake excess soil from the roots
• Divide root-ball with your hands, or two garden forks back-to-back if more leverage is required. If the plant is tough and woody, cut with a sharp knife or even a saw!
• Make sure each new plant has more roots than shoots.
• Replant as soon as possible to prevent plant roots from drying out.
• Keep well-watered in dry spells.
• Reminder - Don’t propagate mint that had rust last year. Dispose of any affected plants and replace with fresh stock.

This method can be used to propagate;

• French tarragon (Artemisia dracunculus)
• yarrow (Achillea millefolium)
• chives (Allium schoenoprasum)
• marsh mallow (Althaea officinalis)
• chamomile (Chamamelum nobile)
• pinks (Dianthus spp.)
• lemon balm (Melissa officinalis)
• mints (Mentha spp.)
• comfrey (Symphytum officinale)
• thymes (Thymus spp.)
• valerian (Valariana officinalis)

Propagation by layering

Difficult herbs to grow from cuttings or seeds, such as bay, can be layered now.

• Select a low-growing branch, less than 60cm long and bend it so that it touches the ground.
• Where it touches the ground, wound the underneath of the branch, by nicking it slightly, to encourage it to root.
• Prepare the ground by removing some of the soil and replacing it with cutting compost.
• Bury the wounded part of the branch in the cutting compost. It may be necessary to use some pegs to pin it down.
• Tie the free end of the shoot to a vertical cane.
• Keep well watered all summer.
• By autumn, it should have rooted. It can now be cut off from the parent plant and potted up or placed in a new position.  Keep well-watered for the next season.

Pest and Disease watch

• Rosemary leaf beetle has become more and more of a problem in recent years, especially in southern counties. Look for brown and dying back shoot-tips on rosemary and lavender, the result of beetles feeding. Adults are usually first seen in late spring. They are around 1cm long with metallic green and purple stripes down their wing cases. Look for groups on stems, or feeding on new growth, as they remain largely stationary on plants until later in the year. Mating and egg laying take place in late summer. Larvae hatch after about 10 days, feed for a while, then drop into the soil where they pupate.
  
  Squash beetles when seen, as vigilance and action now will enable you to break the life cycle of these damaging beetles.

• Mint rust can be carried from one year to the next. If your mint showed signs of yellow pustules last season, get rid of it completely and start with fresh plants. Or grow your own from seed.
• Bring pest-eating predators into your herb garden. Sow seeds of the flowers that they feed on and you’ll have the best pest control ever. Go for open-mouthed annuals (calendula, cosmos, flax, rudbeckia) which provide easy access to nectar. Flower seeds in The Organic Gardening Catalogue are clearly labeled to show which insects they attract.

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