top of page
Sunset View Farm Dahlias (4).png

Farmer Andy's
Dahlia FAQ

All Things Dahlias

Over the years, we've been asked many questions about anything you can imagine concerning dahlias. We've collected some of those most frequently asked questions here for your benefit. We have plenty more we'd like to add as time allows.


In the meantime, also check out our Resources for New Dahlia Lovers post and feel free to email us with any dahlia related questions you may have. We're happy to help!

  • How do I find the eyes on my dahlias?
    The “eye” on a dahlia is a growth point, similar to eyes on a potato. But unlike potatoes, Dahlia eyes occur only on the crown of a tuber, the spot where each individual tuber attaches to the main stalk of the plant. If a tuber does not have an eye (if it’s a “blind” tuber) it’ll never grow anything. You can chuck that baby! Or if you’re brave, make tuber french fries out of it. We’ve heard Cafe au Lait tubers in particular are tolerably tasty. ​ It can be extremely difficult finding eyes most of the time. The best case scenario is if you have a killing frost, then the temperature warms up over the next week or two before harvest. The frost will kill the stalk, then the eyes on the tubers will start to swell or even regrow tiny little shoots which makes dividing them a lot easier. ​ Another option is to store your tubers as clumps, then wake them up one-two months before it's time to replant, so the eyes start to swell. Some tubers take up to three months to eye up nicely. Others will wake up within two weeks. Most are wide awake within one-two months of returning to 60-70 degree temperatures. ​ There are many video tutorials online for finding dahlia eyes, but they’re tough to see even in the best videos. It can be really helpful to take a few undivided clumps out of storage quite early, pot them with the crowns sticking up above ground (they won’t dehydrate) and watch them wake up. You’ll be able to see in real time whether or not something you thought was an eye really was.
  • Are dahlias perennials?
    In warm climates where the ground does not freeze, yes, dahlias are perennials and they will come back every year. However, if you live in a cold place you will need to dig them up and store them inside each year, or cover/insulate them if you leave them in the ground. Otherwise, the tubers will freeze and turn to mush. Fun fact: Every spring here in NJ (where we have very cold winters), dozens of "blind" tubers sprout from our compost pile. This goes to show two things: compost piles stay warm all winter; and spotting eyes on dahlias is hard even for the pros!
  • When or how often should I water my dahlia tubers?
    You should make sure you are planting your tubers in moist but not saturated soil. After planting, don’t water until you see a sprout of about an inch or so above ground, since overwatering before this can cause the tuber to rot. Dahlia tubers have plenty of water in them already! Once you see a sprout a couple inches tall you can begin watering regularly, whenever the soil is dry.
  • How long do dahlias take to wake up (How long do dahlias take to show visible eyes)?
    Every variety is different. Some tubers will show visible eyes within two weeks of being “woken up,” that is, moved to warmer temperatures. Some take two months to show any signs of life, or even longer!
  • How and when do I wake up my dahlia tubers?
    The simplest way to wake up dahlias is just to move them from cold storage to a warmer environment. Room temperature is fine. If your storage solution is well designed, you don't even need to transfer the tubers to dirt or pots. Just move them! At Sunset View Farm we start waking ours up in the beginning of March by taking them indoors from our unheated, attached garage (about 40 degrees) to room temperatures (about 68 degrees) so they are all very nicely eyed up or even sprouting by the time we ship in mid-April. That lets people in warmer climates get them right in the ground as soon as they arrive. We're in northern NJ so we don't plant our own until mid-late May, but it doesn't hurt the tubers at all to have been awakened early. The worst case is you just snip off an over-eager sprout and plant the tuber as normal - it'll grow several more sprouts back promptly. This timeline applied to your situation: take your tubers to warmer temperatures 4-6 weeks before you expect to plant them outdoors.
  • Do I need to support / how should I support dahlia plants?
    Dahlias usually need support or they will fall over and either break or continue growing with bent stems which are useless for bouquets. There are several different ways to support them, including: corralling, staking, and netting. If you have only a few plants, individually staking plants is the best way to go. Use whatever you have: bamboo, wooden stakes, rebar, etc, and loosely tie the plants to the stake. If you have a row or two, corralling works great. Corralling involves tying twine or rope around stakes placed at the outer edge of your row. This keeps plants from falling down away from the row, but you’ll need to make sure the plants are spaced close enough so that they can support each other within the row. ​ If you have many rows, netting is our method of choice. We use Hortonova Trellis netting, purchased in large rolls which cost (as of 2022) about $6 per 60 feet. We run 60 foot rows, with 4’ of growing area in each row. Instead of wooden stakes we use 10 3/8” rebar (more expensive than wood, but lasts forever), 4’ high, placed at each end of the row and at intervals of 15’ on either side of the row. From there we roll out the netting over the rebar stakes, which when properly spaced will give the plastic enough tension to hold itself up without any additional ties. In our opinion, netting is easier to set up, adjust, and take down than any of the other methods! We get our netting from Johnny’s seeds.
  • How do I take dahlia cuttings?
    The American Dahlia Society has a great succinct guide on taking dahlia cuttings, but read on for our take: Taking cuttings is an easy way to get more bang for your buck and grow your collection faster. Healthy plants grown from rooted cuttings will produce blooms and flowers just like a plant grown from a tuber. To take cuttings, make sure you wake up your tubers two-three months earlier than you would normally plant them (we sometimes start 5 months in advance, but we’re overachievers). Some tubers take up to two months to start producing shoots. Some will wake up in a couple weeks. To wake up your tubers, place them in damp potting soil straight up, with the crown exposed. Don’t overwater! The soil should stay slightly damp, never soaked, and never bone-dry. Put the tubers in a warm place. Grow lights are optional at this point. Once the eyes start to swell, make sure the tubers are getting adequate light. Let the shoots grow to at least two inches, then cut the shoot at the base with a sharp knife. Don’t cut into the crown, or you’ll remove the growth point and no other shoots will form. ​ There are several ways to root the cuttings after this point: You can leave them in a glass of water in a warm sunny place (old-fashioned method); you can put them directly into pots with soil that’s kept well-watered; or you can use a growing medium like vermiculite or coconut coir in a 72-cell tray, or similar set up. In any of these mediums, the key components are heat, moisture, and light. Keep the plants about 70 degrees or warmer. Ensure they always have enough water and keep them in a relatively humid environment. And make sure they get 12-14 hours of light per day (dahlias begin growing tubers when day length is under 10 hours, which you don’t want to happen before you plant them outside). With any of these methods, roots can take from one to four weeks to form. Rooting hormone is not necessary, but it sometimes helps speed up the process. Dry or Gel works fine (we use Garden Safe brand). We have tried all three methods and all of them work. The old-fashioned method (rooting in a glass of water) is by far the easiest and simplest if you only plan to take a few cuttings. ​ If you are taking many cuttings and need space efficiency and organization, we recommend you use a 72-cell tray with a water bath and heat mat. If you have lots of space, then you can go ahead and root cuttings in larger pots, just make sure they are kept warm to encourage the rooting process to take place.
  • How long will it take a dahlia cutting to bloom?
    Healthy rooted cuttings will grow, bloom, and produce tubers just like a tuber planted in the ground. Every variety is a little different but generally dahlias take about 8 weeks to bloom after planting.
  • How do I store dahlias over the winter?
    The million dollar question! Everybody has a favorite method. Here are a few methods in brief: Wrap each tuber in plastic wrap and store in your refrigerator crisper Store in peat moss in a cardboard box in a cool, dark, damp place. Store in vermiculite in a plastic tub with a lid in a cool, dark place. Store without storage medium in a five-gallon bucket covered with newsprint in a cool dark place. However you do it, consider these key factors: Temperature, humidity, and air flow. Temperature Dahlias should be stored at about 40 degrees. A little colder or a little warmer is ok, but if they freeze, they’ll die, and if they get too warm, humidity and rot become a problem. A garage, crawlspace, or cold basement often works well. Humidity Dahlias gain and lose moisture in cycles in response to their environment, so they need to be kept in a somewhat damp atmosphere (think how damp the ground is, where dahlias in warmer climates naturally overwinter). To facilitate this, most people use a storage medium. A storage medium has two jobs: it keeps tubers from losing too much moisture, and it absorbs excess moisture respirated over the winter. Most beginners seem to have the best luck with peat moss as a storage medium. The trick is to check it frequently (every two-four weeks) and add moisture if it gets too dry, or leave your storage containers open to airflow if it gets too damp. Air flow Speaking of airflow, you’ll need a container to store your dahlias. Most people store them in plastic buckets or tubs with a lid, filled with a storage medium, since that offers the most control. However, if you have a particularly humid and cold environment relatively safe from critters (like the classic root cellar) you can even use a plain old cardboard box with soil.
  • How does Sunset View Farm store our dahlias?
    We store our dahlias in an attached, unheated garage that stays at about 40 degrees most of the winter. We heat with propane on the rare day the temperature is in danger of dropping below freezing. Our tubers are washed, divided, washed again, and air dried before being placed in bulb crates lined with a plastic bag (the kind with small ventilation holes seems to do best. They are sold as bulb crate liners). We leave the bag open on top and stuff recycled newsprint over the top of the crate, which blocks air entry/egress while absorbing excess humidity, especially during the first few weeks of storage. We do not use any storage medium at all other than the newsprint on top of the tubers. Home gardeners can use buckets or open plastic bins instead of crates with liners. With this method it’s very important to check tubers a couple weeks after initial storage to make sure there is no excess moisture or condensation stuck in the container. If there is, remove the newspaper, allow water to evaporate from the container and tubers, then replace the paper on top. After the first two weeks check, we check tubers every month for moisture build-up. This method works like a charm for us. You can replicate this method at home with five gallon buckets instead of bulb crates and liners. One year we stored 12,000 dahlias in buckets before we made the switch to crates, which are more space efficient.
  • My tubers have some mold or fuzz on them after winter storage. Will they grow?
    It's good to remember (we forget ourselves sometimes) that though the flowers are so gorgeous, and we package up the tubers in pretty boxes, the tubers themselves at the end of the day are roots that go in the ground, and all sorts of things grow on them. As long as the eye is there and the tuber is still firm, a little fuzz or black mold won’t hurt anything. They'll grow beautiful flowers. If you're still concerned about a particular tuber, squeeze it firmly to check for hollow-rot. If it's questionably firm, snip off the bottom third. If the tuber is healthy, this won't hurt it. If it's beginning to rot from the inside out, this will reveal the problem.
  • What’s the best way to ship dahlia tubers?
    Dahlias are not terribly fussy to ship. The key is to ship them early in the season when temperatures are cool but not freezing. Ideally, this should be true both for your region and the destination. However, most places in the US are generally safe to ship to by mid-April so long as the recipient is on the lookout for the box and never lets it sit outside overnight. Ship dahlias in a microcosm of your successful winter storage environment. If you stored your dahlias in bins with peat moss, ship them in ziplock bags in the same peat moss. If you stored them with no growing medium in crates or buckets topped with newsprint (like we do), ship them the same way. Use the smallest box they’ll fit in and make sure there is plenty of padding. Wood shavings and newsprint (our favorite) work best. Loose peat moss or potting soil tend to spill out during shipping, making a mess and reducing the efficacy of your padding. When the box is all packed, give it a gentle shake. There should be nothing at all rattling around. If shipped at the right time of year and packaged properly, dahlias do not need to be shipped priority or overnight. Economy shipping works just fine (wholesale dahlias are shipped in bulk from overseas growers and stored in crates for months at a time - yours will do fine in the mail for a few days).
  • How long do dahlias last in the vase / What is the vase life of dahlias?
    Dahlias last a very long time on the stem, and the plants keep producing blooms as often as you cut the old ones. However, like many other bold, lush flowers, dahlias have a shorter vase life than more spare blooms. How long your dahlias last depend on the variety, on conditions at harvest, and on how you display them, but in good conditions, a good rule of thumb is 5-7 days. The Seattle wholesale growers market has an absolutely fantastic resource on vase life by variety. Definitely check that out!
bottom of page