purple flower with green tufts on cones from aster yellows

Aster Yellows

As with most disease and pest problems, accurate diagnosis is the important part of controlling a problem and doing so responsibly.

In this case, the image shows aster yellows disease on a purple coneflower. Aster yellows is a disease that is spread through insects that suck on the sap of plants. In most cases, it’s the aster leafhopper that is the carrier of the pathogen.

Aster yellows creates distorted flowers with green tufts, chlorosis of the leaves, stunted growth, and green flower petals. Different species may exhibit slightly different symptoms.

It can spread among plants in the Aster family as well as hundreds of other plant species outside of the Asteraceae family. Including lettuce, garlic, carrot, tomato, chrysanthrmum, petunia, zinnia, coreopsis, and perennial weeds like dandelions.

Unfortunately, if you see signs of aster yellows the entire plant needs to be disposed of to avoid spreading the disease. There is no treatment since it becomes a systemic issue and travels down into the roots. Burn your plant or bury it in your compost so it’s completely covered. The disease will not survive once the plant is dead.

You can plant something else as a replacement as it will not transfer through the root system.

Dry and hot summers slow the spread of the aster yellows disease, while cool and moist summers may accelerate transmission.

*Note for MN residents. It is illegal to dispose of plant material in your trash bin. Especially noxious weeds. Letting them die on site is the best way to mitigate further spread. Choose an area, above ground to pile weeds and pull weeds that germinate.

Read more on extension.umn.edu/plant-diseases/aster-yellows

distorted green coneflower afflicted with aster yellows
Grape Hyacinth in bloom

Planting Fall Bulbs for Spring Blooms

By planting fall bulbs now, you’ll be greeted with a warm and blooming welcome that will take your breath away. The anticipation of watching your garden come to life with spring blooms is simply thrilling.

When to Plant

Plant your fall bulbs when overnight temperatures start dropping to around 40° F overnight or 6-8 weeks before the ground freezes. Store your fall bulbs around 60° to 65° F and in a dry area before being planted.

Bloom Time

fall bulb planting bloom times and depths
Bloom times will be indicated on the package of the bulbs. Plant multiple varieties with different bloom times to give you the longest duration of early spring blooms or plant varieties that bloom at the same time for an array of colors!

Where to Plant

Wherever you want to plant, make sure the soil is well-draining. Bulbs don’t like wet feet or else they may rot. Add amendments like compost or topsoil to ensure proper drainage. Try not to plant in low-lying areas where water pools and stays soaking wet. Add Bulb Tone from Espoma to your soil when you plant to give them proper nutrients before and after blooming.

Plant bulbs in full to part sun. Check the bulb packaging to see sun requirements as some can take shady areas.

Layout

Bulbs look best in groups. Consider adding them to areas where you already have perennial plants to fill in bare spots. They will brighten that area in spring and then the foliage will be camouflaged by other herbaceous perennials and shrubs as they fill out.

It’s called “naturalizing” when you plant bulbs in sporadic groups throughout your garden to make it look like a meadow.

Bloom Colors

You may like a certain color repeated throughout your yard or if you want to dive into color combinations you can go back to what we learned in art class and use color schemes! Analogous, complementary, monochromatic, and split complementary colors are color schemes that you can build with flowers and other plants!

Common Fall Bulbs at Drummers

Allium – purple pom poms atop wand-like stems.
Crocus – very early color. Some even bloom in snow!
Daffodil (Narcissus) – sunny yellows and white. These are great in groups. Great for forcing.
Grape Hyacinth (Muscari) – purple or pink.
Hyacinth – the fragrance that will stop you in your tracks! White, pink, purple. Great for forcing.
Tulip – Huge variety of colors, sizes, and bloom times. Great for forcing indoors for indoor bulb gardens.
Snowdrops – small white flowers that hang like a bell.

Cornell University actually did tests with planting bulbs with other perennials to see how they looked. Click here to see the results!