Agapanthus

I went to a very good talk and practical demonstration on Agapanthus last night, and I thought I would try and record some of the main points here. The talk was given by Steve Hickman of Hoyland Plant Centre – a specialist Agapanthus nursery that is one of the national plant collection holders. He said …….

Types There are two main types. Deciduous ones that are hardy and can be grown in the border, and evergreen ones which are generally not hardy north of London. The latter need winter protection and are suitable for pots.

Buds A key element of Agapanthus is that the buds for the next year’s flowering stems form on the rhizomes in the previous year. This has two important implications.

1) Although deciduous plants are hardy down to -15C, the incipient buds are not. Consequently the hardy ones do need a winter mulch of something like bark chippings. If the plant gets frosted, the plant itself will survive but the buds could be affected resulting in no flowers in the following season.

2) The second effect relates to the tales of Agapanthus needing to be congested before it will flower. If you remove an Agapanthus from its pot and can see virtually only root and no compost around the sides, it is pot bound (or congested). But if you can still see some compost – its not.

If you buy a small Agapanthus in a pot which is pot bound and replant it in a larger pot, it will flower the first year because the buds will have already been formed. But it won’t flower for the next year or two, depending on the size of the pot, because it will concentrate on filling the pot with new roots first and won’t start to produce any flower buds till that has done that.

You won’t have a problem re-potting a sizeable clump because, although the plants on the outside will be forming new roots, the plants in the centre will still be congested and hence will flower.

If you want to put some small plants in the border, you can accelerate their flowering by putting, say, three plants in a pot where the bottom has been cut out and then burying the pot in the border. The constriction of the unseen pot will get them to start making buds earlier.

Compost Agapanthus like to be in moist but well drained compost, so the ideal mix is 2/3 multi purpose compost with 1/3 grit or sharp sand. Perlite or vermiculite could be used instead of the grit. These latter two are also helpful in reducing the weight of large pots. Agapanthus is not fussy about the pH of the soil, and does well in full sun or part shade – but not full shade.

Feeding Feed every 2 to 3 weeks from about this time till almost Christmas. Whilst they flower mainly in July and August, they will be producing seeds and buds for the next year till much later in the year. They need lots of potassium (ie tomato type feed) with a recommended N:P:K ratio of 12:12:32. If you feed too much nitrogen you will get lots of lovely leaves but few flowers.

Propagation They are easy to propagate at this time of the year. Either from seed – they won’t come true or flower for 3 to 4 years, or by division. You can lift a large clump and cut it with a knife or any sharp instrument. Throw away any rhizomes that you have cut in two – they will only rot, and then leave the cut pieces for 24 hours before you re-pot them. This will allow any damaged surfaces to dry up and heal. Large clumps, even after dividing, should flower in the same season, whilst smaller pieces will take longer until they have re-filled their contained with roots.

Overwintering Mulch the deciduous ones, and protect the evergreen ones in pots from frost. The pots can be stored in a shed or even be in a cellar – they won’t need any light over winter. Agapanthus likes to be kept cool over winter – ideally at 5C. 10C and over may be too warm and could harm future flowering.

I found the talk most informative, especially the explanation about the buds forming on the rhizomes the year before and its implications. I hope this piece helps others too.

 

That explains a few things regarding flowering them! Thanks for sharing.

Now we just need the list of deciduous and evergreen species/varieties

 

Thanks LongK. I do like explanations. I find it difficult to remember a lot of individual facts - but if there is a logical explanation its very easy. So I was intrigued to learn about the buds forming in the previous year - it explains a lot.

 

Thanks Peter, that made interesting reading.

 

Very interesting Peter, some good info there.
Only ever grown the deciduous types myself.

Just got to say though, I never understand the potbound bit, in order to flower?

Its often said of a lot of plants. Pelargoniums and Strelitzia are just a couple, now Agapanthus.
So why do these plants flower when planted in the ground?

 

Some plants are more likely to flower under stress @pete, usually lack of water so I can understand it happening if they're pot bound too.

 

Yeah but the thing is they flower when not under stress, ie planted with a free root run.
I think its more about establishment rather than potbound which is usually stated, they are two different things.
Flowering under stress will be poorer than flowering not under stress.
Just my way of looking at it.

 

Do they have a "gardening for dummies" name?

 

Hi Lori,

They're known as " African Lilies " or " Lily of the Nile ".

 

Pete - the way I see it - is that Agapanthus has a 'to do' list, which is first put out roots, then produce more plant buds, and only when that's done produce flowering buds. I suspect that its more a matter of producing flowering buds when the other work is done, rather that being under stress. That way a single plant in a border will first produce roots, then surround itself with new plants. The plants on the outside will still be putting out new roots, so won't flower, but the plant in the centre will be constricted by the plants surrounding it so will start to produce flowering buds.

It is interesting that you mentioned other plants. I was wondering how many other plants this might apply too. I should have asked that question, as Steve grows others as well - but you only think of these things too late.

Hi Lori - sorry we don't mean to be elitist by using Latin names. Its just that all the books use Latin names and there are often so many different English names for the same plant - but I should have mentioned African Lilies as everyone knows that name.

 

I think that sums it up nicely. I see a similar pattern in a few of the Amaryllidaceae family. Hymenocallis flowers after division but the year or two after that they will be sulking. Bought bulbs of Sprekelia will flower the year of purchase but having been planted up individually they do nothing for two or three years after.

 

I grow 3 different types. All in pots and stored in unheated greenhouse over winter. As I live in Scotland I've been loathed to plant any of them them outside altho I am going to attempt to plant some of 1 variety (Headbourne Hybrid) outside this season. This is a deciduous variety and hardier than most I think. The other 2 varieties are evergreen. When I ordered the Agapanthus I ordered 3 varieties which were deciduous but the supplier didn't have all I wanted and sent 2 lots of evergreen. I should maybe have refused them but thought I'd give them a go.
I've had all 3 varieties for 3 years, The Headborne Hybrid have done well and flowered fine. The White Umbrella, flowers white as the name suggests! have done equally well and flowers the best, I'm really pleased with this variety and the flower heads are big/foliage good. Purple Cloud the other evergreen has not been good. 2 of the 3 pots of it rotted off during the 1st winter despite the pots being in the greenhouse. The sole remaining pot has not flowered YET. I am going to give it 1 more year and then if still nothing it's going on the compost heap.
I'd be grateful for any suggestions of good deciduous types to buy.The tougher the better for my climate. When you look on the net about them all are deemed "wonderful and free flowering" when in reality they differ quite considerably.

 

Thank you!

@PeterS - I'm not in the least offended by the proper names it's just that quite often plants over here are labelled with their "dummies" name..

 

Hi Lori - The question of names keeps getting discussed. Many common names are very popular and well understood, but common names are not necessarily unique descriptions - for instance, I understand, that in North America a Bluebell refers to Virginia Bluebell (Campanula rotundifolia), but in Europe a Bluebell is Hyacinthoides non-scripta. Virginia Bluebell is also used to describe Mertensia virginica as well.

When I started to garden - not that long ago, I learnt about plants from books and having a scientific background I thought that the Latin names would give a complete and unique identification. They now keep changing the Latin names so no one knows where they are. I grow Iochroma australis, which used to be called Dunalia australis, then Agnistus australis, and should now be called Eriolarynx australe. You can't win.

LongK - I still have a Sprekelia that has never flowered in several years - you seem to be telling me I should persevere.

 

Give it a hot and dry late summer is my other suggestion.