Container grown Agapanthus:
Plant one Agapanthus per pot as they soon grow to fill the
container but they will only flower as soon as their roots have filled the pot
completely. Agapanthus like their roots confined to flower well. You are
better to pot the plants up slowly into a slightly larger pot each time this
way they will flower every year, but if you do not mind waiting then yes
plant one Agapanthus straight into a large container.
Place polystyrene packing chips into base of pot this gives better drainage
and helps keep the heat in the pot. Place 2 or 3 sheets of newspaper on top
of the chips then good soil based compost and plant your Agapanthus into
this leaving a 1-2″ gap at the top of the pot to this add 2″ sized round
dark coloured pebbles this helps retain heat in the compost. Place
container on the sunniest spot in your garden they require full South facing
You can plant in a pot all year round during winter months you need to
bring the pot inside or place below a hedge on a south facing side to help
protect the newly potted plant from frost damage.
Soil based or peat based are both equally good as long as you treat each compost correctly.
Soil based compost add 10% 4mm grit per volume.
Peat based compost add 10% 4mm grit per volume plus slow release fertiliser follow manufactures instructions as per quantity too use.
Fill the compost in around the roots of the plant gently giving the pot a gentle tap to help settle the compost without compacting the compost and blocking the air pores. Water your plants in well until the water starts to run out of the bottom of the container.
Take a used 1 or 2 litre plastic drinks bottle and pierce a small hole in the cap fill the bottle with water and screw cap onto bottle again. Turn bottle upside-down and bury the neck of the bottle in your container this will act as a drip watering system for your pot if you go away on holiday a 2 litre bottle will give the plant enough water for 2-3 days depending on temperature. If you want to slow the drip in the bottle down more place a screw into the hole in the cap this helps to slow the flow of water out of the bottle.
If you use slow release fertiliser this will keep your plant fed for 12 months. If using a soil based compost then from May to September feed your plants every 2 weeks with a powder or liquid foliar soluble feed. Do not be tempted to add more fertiliser than the manufactures recommended dose.
The major pest of Agapanthus has to be vine weevil small white 4-6mm grubs with an orange head. They live in the compost and eat the fleshy roots this is what makes them hard to detect as the damage is done before you see what has happened to your plant. There are products on the market to help prevent the vine weevil going into the compost. You can buy these products as part of a ready made compost or separate in granular or liquid form to add to your compost.
Other pests would be slugs and snails they do not do as much damage to the roots as vine weevil. February 14th is the day to remember to start your attack on slugs and go on the nightshift!! Yes going out at night with a torch is still the best way to see if you have a problem with these pests. If you find a lot then see this link on how to prevent slug damage.