Agapanthus ‘Midnight Sky’

[Andrew in Germany]

I’ve never been very gifted with Agapanthus, and they know it. As far as I’ve been told, they like to be root bound to flower well, which as far as I can see is the only reason to keep them. They don’t live through my winters outdoors in the ground so I’ve kept one over the years in a pot and its roots are probably the only thing left in the pot… and bring it into the greenhouse. I know this must be the reason why it has only ever bloomed once for me and so long ago that I can’t remember what it looks like. But after a visit to my local garden center ( have to leave Germany, drive through the Netherlands and into Belgium and there it is, in Genk) and being bowled over by their Agapanthus collection in every size and in every colour hue of blue possible, I bought one, 20% reduced too making it 19€. It’s called Midnight Sky and is the darkest blue almost deep purple I’ve seen. Here’s a pic as usual. Also would appreciate a bit of advice as to getting it to bloom again. It is certainly not root bound, and the flower is strong, tall and proud. How to get it back again?

[Chad]

It is a myth that they like to be potbound.

They do resent root disturbance, so may not flower the first year after division and then pick up the next year, when incidentally they have more roots in the pot.

Give them enough room to root out, and feed and water well through their growth season.

If they stop flowering either pot them into a tub, or divide them and don't be surprised if they sulk for a year.

Chad

[Andrew in Germany]

Thanks Chad, I think I’ll give it a try.

[MartinNicklin]

Andrew you will not regret growing these. I think in your garden they would really fit in and add some amazing colour. They are tougher than people think especially when established. I used to mollycoddle mine and put tarps over them in winter and all sorts. Now I’m more relaxed and just put a bit of straw around their necks held in place with compost. This gives them some nutrients as well when it degrades over the winter and spring.
I’ve got lots of them. They grow equally well in pots and in the ground, though in pots I regularly feed and water but as Chad says they can sulk when disturbed. I had a big clump of a very floriferous variegated cultivar which I decided to split and move. It was divided into big chunks, flowering sized, most given away, but the piece I kept myself still has not flowered - four years later! Here are some of mine. The new cultivar Black Jack really is VERY dark. The photo does not do it justice.

[Andrew in Germany]

Martin, are you growing all or most of these in the ground? A great selection, they look the business! I like the white flowered with a blue throat. Very peaceful. Lovely.

[MartinNicklin]

Andrew they are a mix of in the ground and in pots. In pots I do the same: just bang some straw on top and hold it down with a handful of compost to stop the wind making a mess. When I see the new shoots emerging in the spring, I just brush the straw and compost away to tidy it up.
They are just coming into flower and bud in my garden at the moment and it looks like it might be a good year for them. I love them and I like them in combo with Crocosmia which I know you also grow.

[Chad]

Hardiness in this genus is unpredictable, but as a rule of thumb the evergreen varieties deriving from A.africanus are only half hardy in most of England. I lost mine in The Beast From the East.

The deciduous varieties are fairly reliably hardy in most of England but in Germany I would expect them to struggle. German winters are significantly colder than British ones.

Chad

[MartinNicklin]

I’ve just checked average winter temperatures for the Aachen area and I don’t think they are too scary. Judging by what else Andrew can grow successfully I think with the precautions similar to those I take many would be OK. Even my evergreen plants got through this last winter - which was by no means an easy one up here - with the same straw round the neck treatment as all my deciduous ones. They have all come through unscathed. Of course, this forum is about pushing the borders and all it takes is one bad winter to wipe out all of our good work, and not just the Agapanthus … but worth a go for their sheer exotic looks. I’ve had them now for 8 years in this garden and for many years in my other (most came with me) and I haven’t lost one yet. A good straw mulch held down with bark or compost will keep those roots snug.

[Andrew in Germany]

Some years ago I bought an Agapanthus divided it into 3, planted one in the ground, another outside in a pot for the winter and the last one in a pot and carted it into the greenhouse every year. The first two died. The 3rd never flowered again! My winters here are from mid Oct when we get our first light frost and loose the sun till around March. Around Jan we can expect temps to sink to -9c for a very short time, and snow. Looks like this. I don't think the UK gets it like this unless it's somewhere up North in the mountains... So I'm never too sure of plants that are just on the border.






However it went from that to this, so it's not too bad. Today's high temp is around 35c.

[MartinNicklin]

Don’t be put off Andrew. Shropshire can be very cold. We had lots of very cold weather and snow last winter and spring down to -10 and quite a few sessions way into minus digits, frosts well into April and very cold nights near freezing in May as well. Just down the road from me is the place which had England’s lowest recorded temperature, something like -27. In my last garden, literally a couple of hundred metres from where I am now, the thermometer recorded -18 in 2010 and for two weeks it never got above freezing with the ground frozen solid! I lost quite a lot but I always protected the Agaanthus and look at them now! Yes The UK does benefit from maritime influences but inland it can be very challenging for growing exotics, plus we don’t get the continental prolonged summer heat to ripen wood and thereby harden off some plants ready for a bad winter. I notice many spots in Germany with very prolonged spells of around 30 degrees and above already this year. Here, if we have a couple of days at 25, it’s a heatwave and we start to hit the panic buttons!!!
I have to say that when I lived in Dūsseldorf, I found the climate similar to here apart from much warmer summers.

Dividing them doesn’t always cause an issue. I’ve just taken this photo of a clump I divided last year and potted up. It is covered with flower buds and hasn’t been affected at all:



Yet this variegated form was very floriferous and grew very large so I divided it several years ago. Still no flowers! Were it not for the foliage it would be composted!




Choose them carefully avoiding the fussy ones and I think they would be fine, some protection afforded. When I see what else you grow outside, I think they are worth a go.
PS for further encouragement: last January in my town 15 days of sub zero temperatures down to -7 on several days and 8 days at zero. Aachen: just a couple of days just below zero.