Jeff Lowenfels: When buying dahlia tubers, look for eyes

Jeff Lowenfels
Bob Hallinen

We have about eight weeks left of the indoor growing season before we can safely plant things outdoors in the ground. That may seem like a long time, but is it? Time is relative. Given what we've already endured winter wise, what's a mere two more months?

The good thing about having only two months left is that we have enough daylight hours that there is no longer a need to use supplemental grow lights when germinating seeds for this summer's gardens and containers. While those who have lights should continue to employ them, those who don't (Really? Nine months indoors without grow lights?) can grow using a southern exposure and get some decent results.

To celebrate, let me mention some of the things we can start this week, and I can't think of a better place to begin than with dahlia tubers. These are true tubers, just like potatoes. Like potatoes, they sprout and grow on their own if you let them. The big difference is the eyes (sprouts), which produce green growth appearing at one end of the dahlia tuber, just at the junction where last year's trunk or stem attached to the root/tuber system. This is the end that goes up when planting.

Anyhow, dahlias are extremely easy to grow and will produce the most fantastic flowers with no effort on your part. There are dozens of sizes and shapes to choose from and local nurseries are stocking them now.

When you buy dahlia tubers, look for eyes. If you are storing tuber clumps from last year (individual tubers multiply during the summer to form banana like bunches), they need to be carefully divided into individual tubers with each bearing at least one eye. This means you need to have a part of the "neck" attached.

Next, lobelias should be started now. Again, there are all sorts of shapes and sizes, trailing and upright, so select carefully and visit more than one company's seed rack to find the proper selections.

Lobelias must never dry out and two months is a long time to nurture something so fussy. If you can't provide proper watering, then don't start them. It takes 20 days for seeds to germinate so have patience. The big trick is that seeds are to be sprinkled on the surface of the soil because they must be exposed to light. Do not cot cover them.

Finally, if you are into vegetables, well fruits actually, you can start thinking about tomatoes. If you look carefully, you will find some of the local nurseries have already started the plants they will be selling.

Only specialty tomatoes will grow outdoors in Southcentral because nights get too cool for fruits to set (look for Russian names and words like "Polar" and ask for assistance). If you want to really grow a crop of tasty tomatoes, you will need a greenhouse or some place where temperatures stay above 55 degrees at night.

You don't have to start all or even any of these plants. In fact, if you are new to Alaska gardening, consider just the dahlias, which are a no-fail plant and will give you a feel for how much work caring for seedlings and tubers can be when you have to do it for two months. With dahlias, however, the results are worth it.

Regardless, start gathering what you need for when you do start a few seeds. All annual vegetable and flower seeds, save those in the cabbage family, should be rolled in endo mycorrhizal fungi, so get some. This includes legumes. Also have on hand the best compost, humus or organic potting soil you can find. Containers, plan labels, a heating mat to speed germination and anything else you need will definitely be available at local nurseries.

When setting up pots and flats to plant in, I advise taking a handful of your media and mixing it with a handful of organic fertilizer. (I like to use bone meal.) This should be placed about an inch or so below where the seed will sit so that its roots will grow into it. You will be amazed what "banding" in combination with rolling seed in mycorrhizal fungi will produce by way of healthy, vigorous seedlings.

Jeff Lowenfels is co-author of "Teaming With Microbes" and author of "Teaming With Nutrients." You can contact him on his website at

Jeff's Alaska garden calendar

-- Flowers to start from seed now: Lobelia, snapdragons, carnation, verbena, pelargonium, malva, petunia, lineria, pansy and viola

-- Veggies to start from seed now: Tomatoes (fruit, I know)

-- Herbs to start from seed now: Thyme and oregano


Jeff Lowenfels