Cannas are really easy to grow in either large pots or the ground but they are frost sensitive and love/need heat & moisture to thrive. If they are to be planted in the ground, wait until after your 'frost free' date, water and fertilize liberally all summer long, then dig up the rhizomes after frost knocks back the foliage. Store them in barely moist soil or vermiculite over the winter in a cool place above 0ºC but below 10ºC.

You can get a head start by planting them in pots first (which you've done) in early April and growing them in a warm sunny place inside. When the time comes to plant them outside, they should be well on their way.

Simon

Thanks Simon

Will they get big enough to bloom and should I have started them sooner, also if I get a huge pot can I put all the rhizomes in 1 pot and seperate when I am ready to put them in the ground. Also I cannot meet those temps when I bring them in for the Winter, the only thing I can do is put them in the fridge till about March, will this work?

Annie

They grow fast for me. Mine are 3" tall right now and I will likely get my first flowers in very early July and continuous flowering until frost (Thanksgiving).

I would recommend having one pot for each location in the garden you intend to plant the cannas. While it's ok to plant rhizomes together in the same pot, they should grow together for the whole season. Separating them while in growth will set them back and delay flowering signifcantly.

Because the rhizomes grow so quickly, I only need to keep one pot of rhizomes over the winter then divide and redistribute the rhizomes in the spring to their individual pots.

If you can find a spot in the house below 15ºC, that will probably suffice. The fridge will work too but I'm not allowed to do that unless I buy my own dedicated fridge (not since my wife wanted to know why I had bought so many onions after I had put my amarylis bulbs in the crisper)

Simon

Do yours stay in the pot all season?
Annie

They do, but only because I have a nice spot on either side of our garage door where they sit on limestone blocks set into the ground. They grow as easily in containers as they do as 'in-garden' plants, as long as you modify their culture appropriately (watering, fertilizer, etc.). If you plant yours in the ground, just transplant them out of the pot into the spot you want them (rather than setting the whole pot into the ground).

If you decide on container growing...I grow mine in 14" pots. I have 'Tangelo', which tops out at 42", and the pots are a just a little small (16" would have been better). If you have taller varieties, you'll need a bigger pot. When you start them inside, start with an 8" or 10" pot, then transplant them into the larger pot when they get moved outside.

Simon

I just got some cannas, unknown variety, red in colour. I had planned to plant three/14" pot to get a nice display. Is this all wrong? Will one tuber provide a nice effect? I'm confused. TIA.

Shady

Shady, I hope they don't burst your pot. The tubers are very strong as they grow, and if crowded can indeed burst a pot.

Thanks jroot. I've never grown cannas before. I've always planted in odd numbers, 3,5,7. I should plant only one canna per pot. Correct? How many blooms from each tuber? I thought only one bloom for each tuber & I'd prefer 3 blooms per pot.

Shady

They grow fast! You'll start with one shoot but before it even flowers, there will already be at least 2 or 3 more starting growth. Once the flowering stem is done flowering (be sure, they often have secondary & tertiary flower stems just below the bottom flower of the primary stem) cut it back to just above soil level (they are similar to bananas, once the stem has flowered and produced seed, it doesn't do anything else). This will leave room for the new shoots as they grow.

I wouldn't put any more than three rhizomes in a large pot to start. You'll have continuous bloom from July until frost, with anywhere from 1-5 blooming stalks at time.

Fertilzer and water...they love both!

Simon

Don't use terra cotta or any kind of breakable pots! I've seen many pots crack from the pressure of the growing roots! I use plastic pots for all mine. In a big 14" or larger pot, you can crowd in three if you want - I do it. They should grow plenty tall in that size pot (but a bigger pot is always going to be better) - last year my tallest one was eight feet tall by the time it was flowering.

I place my pots into tubs of water once a couple of leaves have formed. They are big water hogs and this keeps them satisfied. Many people grow them with the pot partially or fully submerged, as pond plants.

BP

Do cannas do better in soil or water, I can do both. Or do they really care? Does any one know anything about water lilies, speaking of water. Or is that a different page.

Annie

I did an experiment where I placed several pots of cannas in tubs of water (the cannas are grown in soil, with the pot being submerged to some degree in water (halfway in my case)), and I left most in regular pots without the tubs of water.

All the ones in the water grew taller, flowered earlier, and had bigger rhizomes in the fall than the ones not grown in the water. The ones not in the water grew just fine, they were obviously healthy, and got pretty big, but the ones in the water were bigger and still healthy.

BP

Thanks for this information, Bonniepunch. I had been thinking about putting some of my surplus cannas in my pond at the edge, and you have definitely persuaded me. Thanks again.

jroot: Do you have fish in your pond? Cause my Koi will eat everything,

I am having a hard time deciding what or how to put my cannas in the pond, my water lilies are hopeless, they lift them up and eat them. But I love my Koi they are so beautiful, just will have to find a better way for these plants.

bonniepunch: So how many inches do you think above soil level were the Cannas submerged??

Thanks for the info
Annie

How do I get these postings to be most recent first instead of last??

Annie

My cannas started life in six inch pots, then were transplanted into 12-14 inch pots when they had a couple of leaves. The rhizome was a couple of inches below the surface of the soil.

My 12" pot went into a tub of water that rose about halfway up the side of the pot - so the rhizome was above the surface of the water. This set up was only because I don't have a pond, not because I thought it was better or 'right' - I was improvising. I have seen pictures of cannas growing right out of the water (shoots emerging from the water) - the rhizome is obviously underwater. I have also read several accounts of people growing them completly submerged, but I don't recall anything about how they did it (pot, soil, koi/no koi).

If you plant the rhizome in a pot and place this partly underwater (so that the rim of the pot is just above the surface), the koi shouldn't be able to get at it through the pot. If they can, then you might have some dangerous mutant koi on your hands :-)

How do I get these postings to be most recent first instead of last??

You can't. This is a really primitive forum format - there is a strong resistance to change here, so I don't know if they'll ever update it without a major revolt :-)

BP

Thanks for the info. Think I will plant them in both.

Annie

I guess I will pipe in with my two cents :o) I have tons of cannas .. way to many for any sane person to even think about having in one little yard :o)

Here are a few pics of some of the cannas I have grown .. for most of you this is a repeat performance :o)

My yard starts out like this (YUCK)
Note to self get neighbour to cut down the other ceder tree to match the height of mine .. lol
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Back deck
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Front yard
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All of my cannas are started indoors .. yup indoors to give them a head start .. none are planted in water or pots although I have had some in pots and they wonderfully just not a pot they will bust out of .. god forbid if they get even taller in water Bonnie!!! I must give that a try :o) I do water almost on a daily basis but it is so worth it.

This year the yard is changing .. I will be putting in two Musa basjoo and a few other newbies :o) I cant wait to see how it turns out.

Laura

Laura,

I bet you ar elooking forward to transforming that yard again eh? LOL