Eucomis plants are often referred to as pineapple lilies. (Photo from Flickr by Stefano)
Debbie in Winnipeg, Manitoba, asks:
Why won’t my eucomis bloom? They did bloom the first few years, but for the past three, they have grown only leaves. I give them lots of sun and water, and occasional fertilizer. I’ve tried 10-52-10 and 20-20-20. I store them dormant indoors in their pots and then pot them up in fresh new potting soil in early spring until they can go outdoors. I’ve tried smaller pots to see if they prefer being root bound, and larger pots to give the bulbs more space, but still all I get is leaves. Why are they being so stubborn? Do they need to be divided and potted up individually?
From Dugald Cameron, bulb expert:
I’ve occasionally had the same problem. I find most flowering bulbs do best when slightly potbound. A slow-release fertilizer with more phosphorus and potassium than nitrogen might help. Phosphorus and potassium are the last two numbers in fertilizer formulas. Begin to feed plants when they wake up and begin to grow.
Amaryllis in bloom (Photo from Flickr by Maja Dumat)
Sylvain in Montreal, Quebec, asks:
I stopped watering my amaryllis at the beginning of September as usual. The leaves yellowed and were cut off. As I was about to store them for 10 weeks in my cool, dark cellar, they started growing new flower stems! I have been growing amaryllis for 20 years and this has never happened. What should I do?
From Dugald Cameron, bulb expert:
In your case, I suggest leaving the flower stalks and let them bloom. After flowering, follow the steps for overwintering I learned from a customer who collected amaryllis.
After flowering, grow amaryllis on a sunny window indoors. Once temperatures are above freezing, move them to a shaded spot outdoors, watering occasionally to keep them from drying out. I use a slow-release fertilizer with more phosphorus and potassium than nitrogen — indicated by the last two numbers in fertilizer formulas. Stop watering in the fall, bring the plants indoors when overnight frosts threaten and cut off the foliage. Lay the pots on their side in a dark, cool spot. Don’t water until you see a sprouting flower stalk.
Considering the cost of amaryllis, it’s worth trying to get bulbs to bloom more than once year. Big bulbs are worth the investment; small ones should flower the first year, but may not flower the second year because they aren’t big enough.
Dahlias make wonderful cut flowers. If you have a favourite, you’ll want to overwinter it and replant it next year. (Photos by Dugald Cameron)
Colourful dahlias, native to Mexico, make a superb cut flower. They thrive in hot, sunny weather and rich, fertile soil, but they won’t survive freezing temperatures. This means you’ll need to store dahlia tubers over winter if you wish to plant them again next year.
But before learning how to divide and store dahlias, first decide if it’s worth the effort. Unless your dahlias were a spectacular success and you simply must have these exact ones again, why not explore the incredible variety of dahlias out there and buy new tubers next spring? They’re not expensive, and nurseries, dahlia societies and garden clubs would be thrilled to lead you on your dahlia adventure.
If you decide to keep them, next decide if you want to divide them. If you have plenty and no remaining sunny spots to plant more dahlias, skip the instructions on dividing and go straight to storage instructions.
Lifting tubers
The little potato-like tuber you planted in the spring has likely grown into a large, multi-stemmed plant, and the tuber has probably grown huge and multiplied, too. In fact, a dahlia continues to grow until frost turns the stems and foliage into a collapsed sorry version of its former glory. Leaving plants until they’ve been killed to the ground is critical to storage success. The tubers are toughening up and getting thicker skins (a.k.a. ripening). Tubers lifted too early won’t store well.
Cut off the stems, leaving a few inches (about 8 cm) above the soil; the shortened stems make handy handles for carrying the tubers once they’re dug up. Start at least a foot (30 cm) away from the stem and gently lift the whole clump. It’s fragile and there’s probably some water in the stems. Carefully remove loose soil, placing the clump upside down for a few hours to dry out. A warmish, late fall morning is best. They’re less likely to fall apart if they’ve had a chance to dry out a bit.
The second trick is to remember the variety. Record the height and save any photos you’ve taken to help jog your memory next spring. If you’re not planning to divide the clump, skip to storage instructions.
A note about container-grown dahlias: Plants in containers freeze solid earlier than tubers in the ground. Lift these plants as soon as their foliage has been killed. Otherwise, the procedure is the same as plants grown in the ground.
Dividing tubers
It’s easier to divide clumps in the fall after you’ve lifted them than to do so next spring. A clump left until spring becomes as tough as wood over the winter months and hard to divide. The question now is how many more plants do you want? It’s always a good idea to have some spares, but do you need 10 more? If you just want a couple more, then divide the clump into a few roughly equal pieces.
Start by washing the soil off with your garden hose. Cut off the remaining stem as close to the base as possible. Now, use a sharp knife to divide your clump from the top downwards through the stem base, like a pie. Each piece should have a section of the base (also known as the heel) and a single or cluster of tubers attached. Cut out and dispose of any damaged tubers; these will likely spoil in storage.
You may notice clusters of dark bumpy spots on the tubers. These are the “eyes” that will form stems when the dahlia is planted again in the spring. Let your tuber(s) dry thoroughly.
A whole Dahlia root in the spring
Storing tubers
It’s most important that they remain dry regardless of where you decide to keep them. Once dry, you can wrap them in a few sheets of newspaper, taking care to label each piece. You can also put them into individual paper bags, loosely closed. An ideal location is somewhere dark, between 5 and 10 degrees Celsius. They mustn’t freeze.
Mixed callas growing in a container. (Photo by Dugald Cameron)
In the fall, you can store calla and canna plants for next year. Both are easy to overwinter; here’s how:
Overwintering calla lilies
These wonderfully colourful plants are from South Africa. In their natural habitat, they grow and flower during the wet season, going dormant during the following dry season. Fortunately, these bulbs are super easy to store over the winter. They have a tough outer coat and equally tough interior, making them less likely to shrink during storage. Give them what they like and they’ll multiply like crazy.
If you’ve grown them in pots, cut off the foliage and bring them in before frost. Chances are they’re probably wet, and the tubers will be plump and full of moisture. If they’re dug out at this stage, they can be easily damaged, and the wound can cause your tuber to spoil during storage. Bulbs and tubers need to ripen in order to survive dormancy. They will slowly dry out, forming thicker, tougher coats that don’t mind handling. They like a cool, dark (but not freezing) spot.
If you really must unpot them, carefully remove the soil and re-package them in vermiculite or ever-so-slightly moist peat moss before storage. But why bother? This is a messy job and it’s easy to accidentally mix them up if you’re keeping track of different varieties. They’ll actually store far better left alone in their pots. It’s what I’ve done successfully for years.
If you’re wondering where to put all your pots, fear not. You can stack them once they’ve dried out. The only thing to watch for are early sprouts growing as your callas wake up. (They don’t grow too well under another pot!) This shouldn’t happen until late winter, but sometimes they surprise you. Keeping them cool helps prevent them from sprouting too early.
Overwintering canna lilies
These popular plants have adorned Canadian gardens for generations. Their lush, tropical foliage and non-stop flowering are one of the highlights of summer containers and gardens. They’re native to tropical Asia where they flourish in the hot, wet growing season; some species reach seven feet (2 m). Here in Canada, where our winters are hardly hot and tropical, our shorter days and cooler weather signal that it’s time to move them indoors. They hate cold weather, so bring them in when overnight temperatures get into the low, single digits.
Early signs of yellow streak virus on canna leaf.
Canna virus – a bad news, good news story
The bad news: Unfortunately, there is a nasty virus in virtually all the big cannas grown in France, Israel, the Netherlands, Australia and the U.S., which are where almost all the canna sold in Canada come from. The disease was first identified years ago but little has been done to stop its spread. It has spread throughout the large nurseries of the world, with only a handful offering virus-free, healthy stock.
It’s known as yellow streak virus, and the name says it all. It first appears as faint yellow streaks in the foliage, increasingly spreading, eventually leading to distorted foliage and death. Like many plant viruses, it’s spread by sucking insects like aphids. There is no cure. Dispose of infected plants and surrounding soil in the garbage, not in your compost. The tragedy is you can’t see any evidence on the root or even early-season foliage. But the mature foliage in fall will show if the plant is infected, which leads me to…
The good news: Fortunately, the majority of cannas we grow aren’t bought. They’re traded, passed on, shared with family and neighbours or traded at horticultural societies. These have likely been around long before the virus even existed. If they’re healthy they’re probably fine. In fact, several canna nurseries and collections were saved by collecting healthy rhizomes from isolated virus-free gardens. So check your canna foliage carefully. If in doubt, throw them out.
Overwintering
Chop the foliage off a few inches above soil level. Cannas in containers can be brought indoors. If they’re in big pots, you’re better off lifting them as you would those growing in the garden. This requires some care because a healthy canna rhizome (root) will have grown a lot bigger over the summer.
Allow their plump, water-filled roots to ripen a bit before storage. Once ripened, you can remove any soil and place them in clear plastic bags filled with very lightly moistened (not damp) peat moss, storing the sealed bags in a cool, dark place. Check them from time to time to make sure they haven’t rotted (you’ll see a mushy area). Just cut this off, let the root dry off and re-store again in peat moss.
Potted Begonia waking up in late winter (Photo by Dugald Cameron)
It seems a shame, but tuberous begonias are often flowering at their best in late summer, just when it’s time to bring them indoors. Like most bulbs, tuberous begonias need a period of dormancy – several months where it’s dry, dark and cool. My bulbs spend the winter in a dark corner of our basement. I discovered my storage trick by trial and error over the many, many years I’ve enjoyed these amazingly floriferous plants. It’s actually super simple.
It’s best if they first get nipped by frost. Wilted foliage is fine, but the the most important thing is to not let them freeze. Better to bring them in a little early. This tells the tubers it’s time to go dormant.
Be gentle with them at this time of year as their fragile, water-filled stems and swollen tubers are easily damaged. Begonia tubers have thin skins and a tiny nick or scrape can become an entry point for infection that will rot your tuber; minimal handling is best. Bring them inside, pot and all, if they’re potted. If you planted them in the garden, leave as much of the root ball as you can manage. Cut the plants back a bit if they’re huge, but try to leave as much growth as you can.
Leave potted begonias in their pots. Those planted in the garden can be carefully cleaned of their surrounding soil and stored in dry vermiculite, sawdust or peat moss in open paper bags. A cool, dark spot is best. Now you let them dry out, and then remove the stem and foliage. By leaving your tuber unmolested, it can dry (ripen) slowly, forming the thicker skin that helps it retain the moisture it’ll need when it begins to sprout again.
Our modern, thermally efficient accommodations tend to be extremely dry in winter. Indoor humidity varies so check on your tubers from time to time. Give your potted tubers a bit of water if they’re starting to shrivel. Bagged tubers can be removed from their bags (media and all) and given a light misting of water.
Another good reason for these checkups is that your begonias may well start to wake up in February or March which is a good thing. I’ve all too often heard sad stories from begonia lovers with neglected tubers that have grown tall, thin white stems while in storage. This won’t kill them, but will give a poor performance that summer. An early awakening tuber can be restarted early indoors. Remember, with tuberous begonias, the earlier they start the sooner they’ll commence their superb, summer-long display. Besides, aren’t we all dying to get something growing in the depths of winter?
By now some of you may be wondering if this is worth all the bother. Well, you’ll know if your begonias were properly grown if the tuber is larger at the end of the season than when you started. If not, then they were missing something they need. An important lesson that, if acted upon, will make you a better gardener. If it has grown bigger it may be big enough to divide into two. Even an undivided tuber will produce a larger plant with more flowers. Like potatoes, begonias grow from tubers, can be divided provided each piece has an “eye”.
