Dahlias are easy to grow but you have to be willing to put in the work. After a few years of growing dahlias in my dahlia garden, I am confident enough to say I know how to grow great dahlias. I have grown many different varieties and harvested hundreds of beautiful flowers. And I did this without ever using any pesticides, not even organic slug pellets.
Pesticides are dangerous for bees and other beneficial insects. Pesticides get into the soil and groundwater. Because birds and hedgehogs eat insects they are affected too. To be truly hedgehog-friendly you need to stop using slug pellets or pesticides. I am purely growing dahlias for pleasure. I love to have a garden full of beautiful blooms to pick from and have enough flowers to fill vases and give to friends and family. If you grow dahlias for profit and do use pesticides, I understand. But if you have the choice, it’s worth considering.
So here are some simple things you can do to keep your dahlias healthy and productive without pesticides.
Prepare your soil
Soil is the most important thing in your garden. Healthy soil means healthy plants and healthy plants are more pest-resistant. The more you can do to keep your soil healthy, the more productive your garden will be. Apply compost and fertilizer before planting your dahlia tubers. At our dahlia association, compost is purchased jointly and shared among the allotmenteers. For a few years, we used cow or horse manure as a fertilizer. But that manure was very heavy and difficult to spread over the plots, so now we just use cow manure pellets.
Take good care of your plants
Proper plant care is another great line of defence against dahlia insect pests, as healthy dahlia plants are less attractive to pests. Water properly and apply fertilizer. Keep weeds pulled in the area around your dahlias. Weeds compete with your plants for water, food and light. Raising happy, healthy plants is one of the easiest steps toward preventing pests in your garden.
Keep your soil bare
Bare soil isn’t natural. Freshly dug gardens and allotments left to nature will soon turn green with weeds. That’s why in my garden at home I plant ground covers and cover garden beds with mulch. This prevents weeds from taking over and soil from drying out. But leaves and mulch provide hiding places for slugs, snails, earwigs and other pests. So keep the soil of your dahlia beds bare, especially at the beginning of the season because slugs love new shoots. If you want to learn more about planting dahlias in the garden please read my blog post Planning a dahlia garden part 2.
Of course, this isn’t the only way to go. Erin from Floret Flowers uses landscape fabric to cover flower beds. The no-dig method uses cardboard to cover garden areas. I have no experience with these methods, so I can’t tell you what works best. We don’t have any problems with slugs, snails or earwigs so I will stick to what I know.
Water your plants in the morning
You probably know it’s best to water plants in the early morning or evening when it’s cooler. Watering in full sun or on a warm day is not waterwise – as much of the water will evaporate before entering the soil.
Both slugs and snails need moisture and are most active at night or during rainy days. If you water your garden in the evening you will encourage slugs and snails to come out. When you water your plants in the morning the soil will be dry before night falls. That is if it doesn’t rain, of course!
Buy ladybird larvae
Ladybird larvae are nature’s natural pest control. The ladybird larvae eat insect pests such as aphids. After several weeks they will turn into ladybirds that also eat aphids.
Actually, I’m not really sure about this one. I planted nasturtiums as green manure, to feed the soil. But apparently, nasturtiums also attract aphids and other garden pests, so I don’t know if this was a good idea. What do you think, is it safe to grow nasturtiums in my dahlia beds?
Growing dahlias is easy and so rewarding. I hope to have given you a few ideas on how to grow great dahlias without pesticides. If you have any questions, or if you have any other tips/advice on how to deal with pests, please leave a comment. You are also welcome to email me at any time with any questions. But most importantly, I hope you enjoy your dahlias!