How to overwinter aroids?

Gaz · Post by **Gaz** » Mon Jul 30, 2007 8:39 am

Normally we just treat them as annuals and leave them on the ground over winter, and buy them again at the local grocers in spring. We've acquired more varieties this year, including Alocasia macrorhizos and Colocasia gigantea and would hate to lose them. Also we've acquired bigger corms this year and would like to keep them.

So how can we succesfully over winter them?

Will need advice on how to keep a few evergreen over winter, while the rest will have to go dormant.

I was also thinking of digging most of them up and just storing the corms dry (like Dahlia tubers). Should I wait for the growth to be frosted first before digging them up, or dig them beforehand and let the foliage wilt away before storing the corm?

Also, will it harm the corm if I slice off all the green growth while still fresh, so I can safely store the corms (and I can cook the C. esculenta leaves

)

Many questions and many thanks in advance!

Post by **Dave Brown** » Mon Jul 30, 2007 3:09 pm

Hi Gaz n Mark,

There are a few ways to keep Colocasia going over winter. To keep them growing you will need to keep them in some warmth to stop the rhizome going dormant. The temp that this happens is dependent on the variety. Burgundy Stem and Fontanesii will stay green down near to freezing, but will need to be on the dry side. If in a heated Greenhouse/Conservatory/room, they will need some water, but be careful not to overdo it or rot may set in. I water by standing in a dish of about 2cm water for a couple of miniutes, and don't water from the top at all in colder months. If the leaves get tatty cut the leaf off, but I leave the stalks as food production.

Lots more to answer will have to do in istallments as very work busy.

Black Magic is a fusspot not really likeing anything below 7C and if they do go dormant are more difficult to restart.

If you are going to cut the tops off and store dry. leave out until the tops have been frosted off. Then remove all traces of leaves. I do this by pealing them off the rhizome from the outer leaves inward until just a small bud is visible then leave in a cold dry place for a few days. When storing allow plenty of ventilation to avoid the dreaded rot. More to come

Gaz · Post by **Gaz** » Mon Jul 30, 2007 9:06 pm

Thanks Dave! Keep it going as I will take it all on board

Libby · Post by **Libby** » Tue Jul 31, 2007 4:14 pm

Great post Gaz n Mark, I will be following this closely as I too need to learn how to over winter various plants!!!!

Libby · Post by **Libby** » Wed Aug 15, 2007 11:00 am

Decided to bump this up as its feeling a bit like autumn in Wiltshire!!
Rain, dark clouds its even put the chickens off laying properly!!
The earliest I have lit my Rayburn (we don't have gas)since we got it in 1991 was one of the august Bank Holiday weekends before 1995. So I'm keeping my fingers crossed for an 'Indian Summer'!

Gaz · Post by **Gaz** » Wed Aug 22, 2007 12:39 pm

As it feels like autumn is fast approaching more info is needed from the colocasia experts

Post by **Dave Brown** » Wed Aug 22, 2007 3:12 pm

I don't know about all Aroids, but I am putting my Colocasia experience down onto a web page.

Alocasia seem to take a long time to get going from dormancy, so I would recommend keeping them going over winter. They can grow in quite dense shade, so bringing them indoors is a posibilty. Mine left in the unheated covered courtyard sailed through unscathed, getting down to around freezing. They didn't grow, but just sat there waiting for spring.

Colocasia are more tolerant of dormancy so the options are more varied. That will follow soon. Don't worry about overwintering yet. They survive outside quite happily until air frosts which should be a while away yet apart from Scottish Mountains.

Gaz · Post by **Gaz** » Thu Aug 23, 2007 1:44 pm

Thanks for the tip! Until now I've always thoughts Alocasias need full sun to thrive

Post by **Dave Brown** » Thu Aug 23, 2007 6:39 pm

My limited experience is that Alocasia get biggest with plenty of warmth, but I have found warmth and shade produces bigger leaves than warmth and sun. They seem to love the translucent roof of the conservatory, where you can just see a shadow.

My Odora is going mad at the moment. These dull humid days. Dripping all over the carpet, always a good sign with Banana, Alocasia and Colocasia.

Post by **Dave Brown** » Mon Sep 10, 2007 7:34 am

I have decided to put a series of replies on this thread, as I can write IMO, whereas the webpage has to be thoroughly researched. Very, very busy at work over the last couple of weeks and into the next couple due to a new product launch. I might stand a chance of doing something quicker on this thread. The webpage is a way off yet.

Post by **Dave Brown** » Sun Sep 16, 2007 7:09 pm

To Keep Alocasia growing over winter.

Be warned! not all Alocasia are anywhere near hardy, some are fully tropical, others are cold hardy. The cold hardy ones are best overwintered growing as they can be more difficult to start off, and take longer than Colocasia, but this is just one option.

The Alocasia I have grown - Odora, Calidora and Macrorhizza can withstand temperatures close to freezing without going dormant, but don't grow much below around 12C. So I plant mine in a well drained compost, with plenty of sharp grit, keep on the dry side, and avoid watering from the top while not in active growth. Alocasia must have oxygen to the roots all year, unless dormant, so a sharply drained compost is advisable to stop root and rhizome rot. If kept in warmer condition indoors or a heated greenhouse with temps rising above 12C water sparingly by standing pot in an inch of water for a couple of minutes every week or so until active growth commences. If kept in a heated house growth may be at summer levels in which case water when the surface has been dry for a couple of days.

As Alocasia can grow in deep shade in their natural environment, they tolerate winter indoor light very well. Mist leaves if in growth indoors to keep Red Spider Mite at bay.

If they grow too large you can cut the leaves off keeping a small piece of stalk until new leaves grow.

Post by **Dave Brown** » Mon Sep 24, 2007 7:44 pm

Tips for pot grown Colocasia

If they are potted in very moisture retentive compost, remove from the pot and assess how much excess soil is around the rootball. remove any compost with no roots in it. Also tease out the compost from around the roots where possible without damaging them. then repot in as small a pot as will accommodate the rootball adding better drained compost with added grit or perlite. This will help protect the plant from overwatering in winter when growth slows or stops. Keep on the dry side when not in active growth.

Tip for ground grown Colocasia.
Do the same with dug out Colocasia that are to be grown on overwinter. pot up in the smallest pot you can with well drained compost. Coil roots around the pot to fit in.

Libby · Post by **Libby** » Tue Sep 25, 2007 8:19 am

Decidedly chilly here, so will be sorting out plants in between putting up the greenhouse and going up to Worcester this weekend!!!! Thanks for this Dave