Annual or Perennial?
When creating a herb garden or deciding which herbs to grow in containers, it's worth knowing whether your chosen herb is annual, biennial or perennial. Annual and biennial herbs such as Basil, Coriander, Parsley, Dill and Chervil are fast growing and may need to be sown at intervals throughout spring and summer to ensure you have a continuous fresh supply.
Perennial herbs such as Oregano, Mint, Thyme, Sage, Rosemary and Chives are slower growing and will require a more permanent home.
Ideally herbs should be grown in a sunny, sheltered location with well drained soil. If you have heavy clay soil then incorporate some coarse grit and organic matter such as well-rotted manure, compost (new or spent compost) or recycled green waste to improve drainage. You may benefit from growing herbs in a raised bed to ensure sharp drainage.
The best soil pH for growing herbs is neutral to alkaline although most herbs will tolerate a slightly acid soil. If you have very acid soil then add some lime when preparing the planting area. Many herbs such as Rosemary, Sage, Thyme and Lavender are useful for coastal gardens.
Although most herbs prefer a sunny position there are a few which will happily grow in shady conditions and moist soil, such as Chervil, Parsley, Meadowsweet, Mint, Lemon balm and Chives.
Growing Herbs Outside
You can grow herbs outside in a dedicated herb garden, a raised bed, a vegetable plot or even amongst the flowers in your borders! Herbs come in an array of different foliage and flower colours so they can be both decorative and useful for culinary purposes.
When to Grow Herbs OutdoorsIf you are growing herbs from seed then hardy annual or biennial herbs such as Parsley, Coriander, Dill and Chamomile can be sown from March until August.
Sow at intervals of three to four weeks to ensure a continuous supply of fresh leaves. All of these easy to grow herbs can be sown directly into their final position outdoors - this is especially important for Chervil and Dill as they are difficult to transplant successfully.
Alternatively you can sow many of these herbs under cover in seed trays or modules and plant them out at a later date - always follow the instructions on individual seed packets. Basil is only half-hardy so must be sown in spring under cover in warmth. Seedlings can be pricked out and grown on in warmth; planting out after all risk of frost has passed. You may find basil performs well indoors on a sunny windowsill if the summer is particularly wet or cold.
Seeds of perennial herbs such as Sage, Rosemary, Chives and Fennel should be sown in the spring under cover in warmth, and then potted on when large enough to handle. Harden off plants in a cold frame before planting out into their final positions.
Where to Grow Herbs Outdoors
Growing herbs outdoors in a dedicated herb garden makes harvesting easier and will create a rich scent on hot sunny days! You could make a herb garden quite ornamental by combining the silver-grey foliage of lavender or sage with the blue flowers of borage or the orange flowers of Calendula (Pot Marigold) (both of whose flowers are edible). There are also great variations in foliage colour with herbs such as Thyme, Basil.
Herbs also make a great addition to flower beds and borders if you don't have the space for a dedicated herb garden. Use herbs with colourful leaves to offset flower colours or to provide different textures throughout the bed. Try using low-growing herbs such as Chives and Thyme as an informal edge to a path. Herbs such as Thyme and Creeping Savory can also be planted in the gaps in paving and patios and will withstand light foot traffic; releasing their delicious scent when walked on. The tall, feathery foliage of fennel looks good in a herbaceous border and the yellow flowers are attractive to bees and butterflies.
Growing herbs in the vegetable garden is a good way to obtain large quantities of your favourite herbs and to allow for successional sowing of fast-growing types. Parsley, Coriander, Dill and Chervil can be sown in rows directly into the soil amongst the vegetables, or as an edging to beds. Sown in late summer, herbs such as Coriander, Parsley and Chervil will continue to grow throughout winter if given protection with a cloche.
Growing Herbs in Pots and Containers
Growing herbs in pots and containers is a great way to grow fresh produce if space is limited. Place them outside your back door for easy harvesting when cooking! Choose relatively deep pots, especially for large shrubby herbs such as Bay trees and Rosemary. The best compost to grow herbs in is loam-based compost such as John Innes. Feed your pot-grown herbs regularly with a balanced fertiliser throughout the growing season, following the manufacturer's instructions. Over-feeding can cause the leaves to lose their pungent flavour so don't be too generous. Make sure the container has drainage holes and is raised up on bricks or 'pot feet' to prevent water logging in the winter. It is also worth protecting pots in severe icy weather by placing them against a house wall and/or wrapping the pot in bubble wrap.
Some herbs such as mint and Sweet Woodruff can be invasive and it is a good idea to grow them in sunken containers (old buckets or plastic pots) in the ground to restrict their root growth. Make sure the container has drainage holes as water logging will kill the plant. Plant the container so the top is level with the soil surface and cover over with a thin layer of soil to hide the pot. When growing mint in a container it is beneficial to lift and divide the plant each year to maintain health and vigour.
Growing Herbs Indoors
Growing herbs indoors is convenient for harvesting and great for those without gardens. It also extends the season for annual herbs so you will have fresh produce all year round! Suitable herbs to grow indoors on the windowsill include Chives, Parsley, Basil, Coriander, Marjoram, Dill and Mint. Try our 'Herbs for Windowsills' collection for a good start to growing herbs at home. mint in pot Simply sow the seeds on the surface of damp, free-draining seed compost and sprinkle lightly with vermiculite. Cover the container with a clear plastic bag or piece of glass and place somewhere bright and warm for the seeds to germinate (about 18-20C). Once germinated remove the cover and grow on. Herbs need a bright position to grow well. You can treat windowsill herbs as cut-and-come-again crops, harvesting regularly to encourage new growth.
A few herbs growing outside can be lifted, divided and brought indoors for the winter. Chives and Mint are ideal for this technique. Simply lift the plants in autumn and divide the clumps into smaller pieces. Plant up the divided pieces into pots of ordinary multipurpose compost, water well and cut back the top growth to leave about 10cm. In the spring, plant the herbs back in the garden to allow them time to recover over the summer.
Herbs are relatively low maintenance unless they are growing in containers where they will require routine watering and feeding (see 'growing herbs in pots and containers' above). Trimming herbs in the spring will encourage a flush of new healthy leaves. It's also best to dead-head your herbs as the flowers start to fade to channel their energy into leaf growth. You can trim shrubby herbs such as Lavender and Thyme after flowering to make flower removal easier. In the autumn it's best to leave any dead foliage on the plant to help protect it throughout winter. Make sure you clear any debris and fallen leaves off low-growing herbs such as Thyme and Lavender to prevent fungal diseases and unsightly gaps forming. It isn't necessary to mulch your herbs with the exception of Mint, which prefers moist growing conditions and would benefit from mulching in the spring.
You will find after a few years that your container-grown herbs may start to look weak and dry out quickly; these are all signs the plant has become pot-bound. At this stage it's best to re-pot your herbs into a fresh container, teasing apart the roots first and removing as much of the old compost as possible. If re-potting isn't an option then simply replace the top inch (2.5cm) of soil with fresh compost and a slow-release fertiliser. Well-rotted manure is also a good top-dressing.
When harvesting herbs, remove foliage from the outside of the plant, allowing new leaves to develop in the centre. As a general rule don't pick more than a third of the plant's foliage at a time to enable it to recover. Herbs are excellent for freezing enabling you to enjoy their flavours all year round. This is especially useful for fast-growing herbs such as Coriander, Parsley and Dill and can help you resolve a glut! You can either freeze whole sprigs in a freezer bag or freeze chopped herbs with water in ice cube trays. Herbs are best harvested in the morning before any essential oils evaporate. You can harvest outdoor evergreen herbs such as Rosemary, Sage and Thyme sparingly all year round but be aware that no new growth will occur until spring.
Herbs are some of the easiest plants to cultivate so why not give herb growing a go this year! Click here to view all herbs.
Written by: Sue Sanderson
Original Source: https://www.thompson-morgan.com/how-to-grow-herbs