Growing Herbs
Jackie Anstis's advice and tips for successful herb growth in containers.
Growing herbs in containers of any kind is basic Gardening common sense combined with some practical care. All herbs can be grown in pots so long as their basic grown requirements are met.
There are various reasons for wanting to grow herbs in containers. For example, culinary herbs growing by the back door in easy reach of the kitchen; a courtyard garden; an established garden dominated by large tress and shrubs with hungry roots; a shaded garden with only limited and season oriented sunny spots; to contain herbs with a 'we will conquer the world' complex; using special containers to add height or accents in garden beds.
Whatever your reason you have to provide growing conditions suitable for the herb that you are planting in your pot. So the questions you have to ask yourself are these:
- Does it like full sun, morning sun only or shade ?
- Does it like dry, moist or wet conditions ?
- Does it spread, or
- Can I plant it in a large pot with other herbs (or flowers or veggies) ?
- Is it suitable for a hanging pot?
- Is it a hungry feeder ?
- Does it die down in Winter ?
- Will I need to move int pot seasonally to provide the desired climate ?
- How big does it grow ?
- Does it have deep growing roots ?
These basic questions when considered before planting up will help to provide good growing conditions for your chosen herbs.
Beside the container type and size, the next important question is potting mix. I prefer to buy the best quality organic potting mix and then add extra water crystals. Depending on the conditions you are trying to create you might also add some well-rotted compost for extra food, fine gravel or coarse river sand for extra drainage, a small quantity of pulverised (i.e. like a gritty powder) clay or some coconut fibre to increase water-retaining properties. (Coconut fibre is lighter for hanging baskets.)
As far as drainage is concerned, with the exception of those plants that like wet conditions like the mints, placing containers up off the ground is the best way to provide good drainage. I haven't added broken crocks, bricks or small rocks to the bottom of my pots for a very long time, although on occasions I have added some charcoal but only if I have it to hand. The current consensus says that rocks etc are not necessary if you are using a good quality potting mix, but if using all your own compost you might have to make a judgement call on this point. The other thing to consider here is the size of the drainage holes in the bottom of the pot - if you feel they are too few or too small then I would suggest enlarging or increasing the number with a drill. If however, the holes are too big, then placing some flyscreen mesh or rubble over the holes will help to stop, or at least , slow down the rate of soil falling out of the pot as you water. Flyscreen mesh is preferable if the pot has to be moved seasonally.
After saying all that, if your pots are small then standing them in a saucer so that they can absorb the drainage water during the day, especially in hot weather, would be an advantage. If you find there is still water in the saucer at the end of the day, then you may be overwatering for the weather conditions, and you will also be providing a mosquito breeding home.
When planting up try to leave the level of the potting mix below the tip of the pot, say 1 to 2cm in smaller pots, and 3-4 cm in larger ones. (These fairly precise measurements are provided by Penny Woodward.) This means when you are watering, the water had time to pool on top and then be absorbed into the potting mix without spilling over the edge and running away on the ground.
Obviously, like all plants, your herbs need more water in Spring and Summer when they are growing vigorously and evaporation is higher. Those herbs with lush and juicy leaves (e.g. basil) ma need to be watered every day in Summer and probably won't mind a mist spray as well on hot days , but again, this will depend on the climatic conditions n your personal garden. Let the surface soil dry out between watering but if the leave start to wilt and don't recover overnight then you know you need to water more frequently. In Winter don't overwater your pots, and after a couple of hours empty the saucer of water as cold waterlogged soil can cause root rot and you plant will die.
If you decide to plant up a large pot with a variety of herbs, or window box or a strawberry pot, then you again need to consider the growing conditions for each herb and group your herbs accordingly.
The following (short) list are herbs which are happy growing in pots, but any herb can be grown in a suitable container if its required growing conditions are satisfied.
Chives Chamomile Dill Chervil Caraway
Coriander Lemon Grass Thyme Lavender Rocket
Mint Watercress Basil Oregano Marjoram
Parsley Rosemary Anise Sorrel Sage
Aloe Vera Summer Savory Winter Savory Violets Lemon Balm
Heartsease Salad Burnet Landcress Chamomile Borage
Plastic and glazed pots retain water better then unglazed terracotta ones which will need more frequent watering. Plastic and polystyrene boxes are much higher if you are intending to move your herbs around otherwise place your pots on wheeled stands. If grouping your pots together, then you can use the taller or tougher plants to shelter the more delicate ones from sun and wind. Grouping a number of pots together helps to create a micro-climate.
Any plant growing in a pot requires more feeding than those growing in the ground, as watering leaches some of the nutrients from the potting mix. Liquid seaweed fertilisers applied with a watering can as per the manufacturer's instructions will keep your herbs growing happily. If not repotting in the Spring then replace the top few centimetres of soil with fresh potting mix and well-rotted compost to revitalise your pots. Depending on the rate of leaf growth and root development of a particular herb, you will need to re-pot every 2-3 years. If planting a new plant in a previously used pot then hygiene has to be considered. Empty the pot then wash in warm soapy water, followed by an overnight soak in a water/vinegar mix, then fill with fresh potting mix and pot up.
In early Autumn I like to give my potted plants a small feeding boost with slow-release fertilizer to help them add to the stored starches in their roots to see them through the Winter.
Further information may be obtained from the following books:
'An Australian Herbal' by Penny Woodward
'Growing Easy Herbs for beauty, fragrance and flavour' by Penny Woodward
"Herbs for the Hole and Garden' by Shirley Reid
'Herbcraft' by Nerys Puschol & Dhenu Jennifer Clary
'Herbaceous' edited by Sarah Baker.
Jackie Anstis's advice and tips for successful herb growth in containers.
Growing herbs in containers of any kind is basic Gardening common sense combined with some practical care. All herbs can be grown in pots so long as their basic grown requirements are met.
There are various reasons for wanting to grow herbs in containers. For example, culinary herbs growing by the back door in easy reach of the kitchen; a courtyard garden; an established garden dominated by large tress and shrubs with hungry roots; a shaded garden with only limited and season oriented sunny spots; to contain herbs with a 'we will conquer the world' complex; using special containers to add height or accents in garden beds.
Whatever your reason you have to provide growing conditions suitable for the herb that you are planting in your pot. So the questions you have to ask yourself are these:
- Does it like full sun, morning sun only or shade ?
- Does it like dry, moist or wet conditions ?
- Does it spread, or
- Can I plant it in a large pot with other herbs (or flowers or veggies) ?
- Is it suitable for a hanging pot?
- Is it a hungry feeder ?
- Does it die down in Winter ?
- Will I need to move int pot seasonally to provide the desired climate ?
- How big does it grow ?
- Does it have deep growing roots ?
These basic questions when considered before planting up will help to provide good growing conditions for your chosen herbs.
Beside the container type and size, the next important question is potting mix. I prefer to buy the best quality organic potting mix and then add extra water crystals. Depending on the conditions you are trying to create you might also add some well-rotted compost for extra food, fine gravel or coarse river sand for extra drainage, a small quantity of pulverised (i.e. like a gritty powder) clay or some coconut fibre to increase water-retaining properties. (Coconut fibre is lighter for hanging baskets.)
As far as drainage is concerned, with the exception of those plants that like wet conditions like the mints, placing containers up off the ground is the best way to provide good drainage. I haven't added broken crocks, bricks or small rocks to the bottom of my pots for a very long time, although on occasions I have added some charcoal but only if I have it to hand. The current consensus says that rocks etc are not necessary if you are using a good quality potting mix, but if using all your own compost you might have to make a judgement call on this point. The other thing to consider here is the size of the drainage holes in the bottom of the pot - if you feel they are too few or too small then I would suggest enlarging or increasing the number with a drill. If however, the holes are too big, then placing some flyscreen mesh or rubble over the holes will help to stop, or at least , slow down the rate of soil falling out of the pot as you water. Flyscreen mesh is preferable if the pot has to be moved seasonally.
After saying all that, if your pots are small then standing them in a saucer so that they can absorb the drainage water during the day, especially in hot weather, would be an advantage. If you find there is still water in the saucer at the end of the day, then you may be overwatering for the weather conditions, and you will also be providing a mosquito breeding home.
When planting up try to leave the level of the potting mix below the tip of the pot, say 1 to 2cm in smaller pots, and 3-4 cm in larger ones. (These fairly precise measurements are provided by Penny Woodward.) This means when you are watering, the water had time to pool on top and then be absorbed into the potting mix without spilling over the edge and running away on the ground.
Obviously, like all plants, your herbs need more water in Spring and Summer when they are growing vigorously and evaporation is higher. Those herbs with lush and juicy leaves (e.g. basil) ma need to be watered every day in Summer and probably won't mind a mist spray as well on hot days , but again, this will depend on the climatic conditions n your personal garden. Let the surface soil dry out between watering but if the leave start to wilt and don't recover overnight then you know you need to water more frequently. In Winter don't overwater your pots, and after a couple of hours empty the saucer of water as cold waterlogged soil can cause root rot and you plant will die.
If you decide to plant up a large pot with a variety of herbs, or window box or a strawberry pot, then you again need to consider the growing conditions for each herb and group your herbs accordingly.
The following (short) list are herbs which are happy growing in pots, but any herb can be grown in a suitable container if its required growing conditions are satisfied.
Chives Chamomile Dill Chervil Caraway
Coriander Lemon Grass Thyme Lavender Rocket
Mint Watercress Basil Oregano Marjoram
Parsley Rosemary Anise Sorrel Sage
Aloe Vera Summer Savory Winter Savory Violets Lemon Balm
Heartsease Salad Burnet Landcress Chamomile Borage
Plastic and glazed pots retain water better then unglazed terracotta ones which will need more frequent watering. Plastic and polystyrene boxes are much higher if you are intending to move your herbs around otherwise place your pots on wheeled stands. If grouping your pots together, then you can use the taller or tougher plants to shelter the more delicate ones from sun and wind. Grouping a number of pots together helps to create a micro-climate.
Any plant growing in a pot requires more feeding than those growing in the ground, as watering leaches some of the nutrients from the potting mix. Liquid seaweed fertilisers applied with a watering can as per the manufacturer's instructions will keep your herbs growing happily. If not repotting in the Spring then replace the top few centimetres of soil with fresh potting mix and well-rotted compost to revitalise your pots. Depending on the rate of leaf growth and root development of a particular herb, you will need to re-pot every 2-3 years. If planting a new plant in a previously used pot then hygiene has to be considered. Empty the pot then wash in warm soapy water, followed by an overnight soak in a water/vinegar mix, then fill with fresh potting mix and pot up.
In early Autumn I like to give my potted plants a small feeding boost with slow-release fertilizer to help them add to the stored starches in their roots to see them through the Winter.
Further information may be obtained from the following books:
'An Australian Herbal' by Penny Woodward
'Growing Easy Herbs for beauty, fragrance and flavour' by Penny Woodward
"Herbs for the Hole and Garden' by Shirley Reid
'Herbcraft' by Nerys Puschol & Dhenu Jennifer Clary
'Herbaceous' edited by Sarah Baker.