THE “VSD” KIT FOR DAHLIA PLANTING SUCCESS
SUGGESTED SHOPPING LIST:
Do you need ALL of these things? No. But with a little love and TLC, your dahlia will produce that much more beauty! These are the things and products that dahlia superstars have recommended to us over the years, but there are a great many other products that will serve you well also! With that said, here’s our list:
1. A great tuber (we’ve got you covered there!)
2. Osmocote (it’s a granular fertilizer, a small bottle is fine)
3. Bone Meal (another fertilizer)
4. A 5 or 6’ stake (to support your dahlia)
5. Sluggo (to protect young dahlia shoots, a favorite snack for slugs and bugs)
6. Horticultural oil (what we spray weekly to deal with powdery mildew, an omnipresent issue for dahlias in most areas, certified for organic gardening) Things like neem oil can work as well, but neem is difficult to work with
7. Captain Jack’s Deadbug Brew (to deal with the invisible and nearly invisible bugs that can stun and stymie dahlia growth like thrips and aphids, certified for organic gardening) It’s pricey, but effective! Other options available here as well.
8. Velcro ONE-WRAP Growing Ties (a fun, inexpensive, and versatile product we use to tie our dahlias to our stakes)
WHEN TO PLANT: Dahlias like to be planted in warm and well-draining soil in the Spring, after the danger of frost has passed (not too much of an issue in California! Trying to plant after the winter/early Spring rains can be wise as well, as dahlia tubers do not want to sit in water before they develop their network of fine roots for absorbing water – they can rot, which would be a downer. mid-April through late May are all fine times! You may get June/July flowers depending on the variety and when you plant, but dahlias are generally “fall flowers,” producing blooms from late July until October/November. Dahlias generally produce their blooms 90 days from when you put them in the ground… some bloom earlier, and some (mostly larger “dinnerplate” varieties) can take 120 days to bloom. So be patient… it’s worth it!
WHERE TO PLANT: Dahlias like full sun – at 6-8 hours of direct sunlight if possible. If planting in a hot climate, it’s best to plant them where they will might get afternoon shade. If the dahlias are shaded, they will spend more of their energy growing to catch more sun, and they will end up being “leggy” with less blooms. Dahlias prefer well-draining soil – if they have “wet feet” for too long in poorly draining soil, it increases the possibility of tuber rot.
HOW TO PLANT: With your supplies ready and sunny spot picked out, dig a hole 4-6” deep that is big enough for you to put your tuber down into. If the soil is dense, consider working the soil in the area (with a rototiller, broadfork, or your own two hands) to help the tuber’s growth. Into the bottom of the hole, drop 1-2tsp of Osmocote, and a small handful of bonemeal (if you’re using those products), and then stir up the dirt at the bottom of the hole a bit. Then put your tuber down in the hole, lying on its side like it is taking a nap. You want the “eye” of the tuber (the protrustion/stalk of plant that is beginning to grow out of the tuber) to be pointing upward. At this time, push your stake into the ground near the “eye” of the tuber if you have it – this way, you don’t have to drive your stake into the ground later and risk damaging your plant’s roots later in the season. That stake will look lonely at first, but it will soon have a beautiful and vigorous plant growing up alongside that will need support to be at its best, depending on the variety. Then cover your tuber up with dirt, and wait! We generally “water down” our tuber, meaning we give is a decent drink at planting time, but we do not water it again until it’s shoot is up above the ground. This may take several weeks. Patience is required at this stage! Overwatering before the shoot is aboveground can lead to tuber rot. And try to refrain from brushing the dirt aside to see where your shoot is – you could damage the shoot in the process, which would be a bummer. (We know it’s hard, haha!) If planting multiple dahlias, plant them about 18” apart.
HOW TO WATER: Dahlias prefer a deep watering a few times a week – one to two in mild weather, more frequently in hotter weather. In hot weather, your dahlias will get a little “wilty” during the day, which is normal. If they don’t bounce back in the cool of the evening, however, that could mean they need a drink. Water at soil level, not overhead if possible. Overwatering can hurt your plant, and increase the possibility of tuber rot.
AS YOUR DAHLIA GROWS:
Early stage – when your dahlia first sends up its shoot above ground, it presents a ripe target for slugs and bugs to munch on. Sprinkle Sluggo liberally to protect the young shoots at this stage.
Growth stage– when your dahlia has three mature leaf pairs (it will probably be around 8” to 1’ tall at this stage), we recommend pinching/snipping out the center shoot just above the third full leaf pair. This will cause the plant to send out more laterals, giving you a more compact and productive plant. Once your plant is around 1 ½’ to 2’ tall, consider spraying weekly with the combo of Captain Jack’s and Horticultural Oil preventatively for bugs and powdery mildew – once powdery mildew gets established on your plant, it is hard to remove. Make sure that you’re watering deeply 2-3 times a week!
Blooming stage – Each of those laterals that popped out when you pinched out the center of the plant should be topped with a bud (or buds) – all the waiting has paid off! Some varieties will have two, three, or four buds on the same shoot – we recommend that you “disbud” by pinching off the other small buds right below the main bud so that the main flower can grow larger, fuller, and with a better stem. And once that flower has fully opened, you should “deadhead” your blooms, removing to either display or dispose of. This keeps your plant vigorous and productive – it will send out more laterals for MORE flowers when you remove the flower! Your plant should be productive for months in the right conditions.
Waning Stage – after a season of producing gorgeous blooms, your plant will start to slow down as the days get shorter and cooler in October/November. If you live in an area where frosts occur, the first “killing frost” will put an end to your season! But if you don’t, you can stop watering once your plant starts dying off on its own – the plant aboveground will die, leaving the roots behind to spring up again next season! Once the plant has spent its energy, looking yellowed and falling over, cut the main stems off 4-6” from the ground. Let them rest below ground for a few weeks, or longer if you’re going to let them winter outside. Check our website for information about digging and dividing your tubers if that is something you’re interested in!
PEST AND FOILAGE ISSUES: We recommend spraying preventatively on a regular basis (per product instructions) once your plants are established, and maybe 18” tall. Check the labels of your products to make sure that the products are safe for your environment, pets, and beneficial insects. KEY: especially with horticultural oil, but with all products, spray in the early morning or late evening to
FREQUENTLY ASKED QUESTIONS:
Should I fertilize my dahlias? There is a lot of conflicting wisdom on the fertilizing of dahlias… long story short, we don’t fertilize much! Aside from what we put in the hole with the tuber initially, we do very little fertilizing and our plants are very happy. We do till in a healthy amount of organic compost annually to promote a healthy soil environment, and that can make a big difference over time. Overfeeding your dahlias can actually have a negative effect on them. When in doubt, use less!
Can I grow my dahlia in a pot? Yes! We grew our first dahlias in pots. We recommend a decent sized pot – something like a 5 gallon to give the roots room to spread and support a vigorous plant. Put it in a place that gets 6-8 hours of sun a day, and fill the pot with soil that’s 1 part garden soil with 2 parts potting soil.
OTHER GREAT RESOURCES:
San Francisco Dahlia Society Growing Guide – sfdahlias,org/growing-dahlias
A great well of wisdom for all things dahlia. Most of what we have learned we have learned through the generous sharing of many, and for that we are grateful!
American Dahlia Society – dahlia.org
Tons of great resources here for learning more about dahlias!
The Vallejo Street Dahlias Instagram – Instagram.com/vallejostdahlias
We post a ton of content here, including instructional videos for every facet of growing dahlias!