Fall Gardening Tips for Zone 4

Fall Gardening Tips for September Through November:

Below are fall gardening tips for gardeners in zone 4. Your timing may be different depending on your location. These same tips have been featured in a recent newsletter. To sign up for our newsletter please visit our website and enter your email.

Fall is a great time to plant hostas!

Hosta roots continue to grow until the ground is frozen. We have planted Starter TC hostas as late as the second week of November in Minnesota while it was snowing, and they did great.

The one exception might be with fragrant hosta varieties that evolved further south in eastern China from H. plantaginea. However, these fragrant varieties are often hybridized with more cold tolerant hostas so it is difficult to predict. To over winter well, they might need to get more established before planting or make sure you cover them through the winter.

Hostas planted now will come up looking fresh in the spring. A cold winter dormancy triggers plant hormones, called vernalization, that make the plant better.

Do not fertilize after July 31st. Your plants need to slow down so they can go dormant.

We recommend you label your plants before winter with a durable plant identification marker. The styrene labels that come with our plants or from other vendors get brittle, break, or come out of the ground easily.

From our experience and those of our customers, it is very frustrating to not be able to remember your plants’ names. Our IDeal Garden Markers business offers unique stake and nameplate options, custom engraving, and labeling services and products.

fall gardening tips

Water your plants in the fall.  Dry conditions during this period before dormancy leave the hostas subject to crown rot. In addition, oxygen in the root area creates healthier plants. Remember that hostas planted under trees may need extra water as the tree’s foliage may prevent the water from getting to the hostas, and their roots compete with hostas for what moisture there is.

Slugs: You will get “most bang for your buck” by putting down slug killer just before the slugs lay their last batch of eggs. In Minnesota that is often around the second week of October. For more information on slugs and other hosta pests, see our Hosta Pests Info page.

Foliar Nematodes:  These microscopic worms that leave brown streaks in your hosta’s leaves start to appear as early as late June in the south and the third week of August to the third week of September in the north. HostasDirect, Inc. has never had a foliar nematode reported in the plants we have sold in 9 years. More information on Foliar Nematodes here!

With our Starter TC and Advanced Starter, you are assured of a clean plant as they are grown in sterile clean room environments and virus tested.

Our Mature Divisions were all started from Starter TC – and we have never had one complaint.

Removing blooms or seeds: To help the bees and other pollinators, we recommend you please leave your blooms on your plants until the blooms expire. Then, you can cut off the blooms before they go to seed. Removing spent flowers before seed production will allow more energy to go into the plant.

Should you cut off your hosta’s foliage before winter? Doing so saves a lot of work in the spring. In addition, some gardeners think cutting off and removing foliage creates less of a haven for foliar nematodes, fungal diseases and slugs, and your yard looks clean in the spring.

Fall Gardening Tips for November or December:

Do NOT use wood chips for winter cover! Wood chips may cause your plants and their roots to rot.

For HostasDirect’s recommended winter mulch method, see our Overwintering Perennials Page.

Cover some perennials just after the ground freezes!  Covering is cheap insurance to protect your investment of time, money, work and emotion. We recommend covering all first year perennials you purchase from us. In particular mini and smaller hostas (as they have more shallow roots), hostas and coral bells planted later in the season, and fragrant varieties of hostas. Beware of voles and mice.

How and what to use for covering plants: In the first year, after the ground is frozen, protect your hostas and coral bells with 6” to 1’ of straw or leaves (in a bag or secured by other means so they don’t blow away). This helps stabilize soil temperature and moisture ranges, reduces freeze / thaw, and prevents hostas from growing too early in the spring only to be damaged by frost or snow.  See an illustration of this method here.

The benefit of snow: Snow acts as insulation and keeps the soil temperature warmer and more even. We worry when there is little or no snow and the temperatures are very cold and prolonged!

If you follow the above fall gardening tips, your plants should come up looking fresh in the spring. Please note that these tips are for Zone 4. Your timing could differ based on where you are located.

Disinfecting Garden Tools Properly

Killing diseases on your garden tools

Garden tools and plants are expensive.   It is important you take care of both and try not to get plant materials that are infected in your garden in the first place!

One of the most, if not the most famous botanist in the world regarding shade perennials and in particular hostas is W. George Schmid.    He has authored such scholarly books as, “The Genus Hosta” and “Encyclopedia of Shade Perennials” and is a frequent contributor to “The Hosta Journal” and other scholarly works.    I asked George recently if he had seen any studies regarding how long to disinfect garden tools, which is increasingly important to prevent the spread of foliar nematodes and other garden diseases.   Here is what George wrote:

“To really disinfect your equipment, it must be very thorough. Brand new tools you can dip, but most of have those old, well used tools.  For those, use 1 part chlorine bleach to 10 part clean water solution.  It is important to wash the dirt off your equipment prior to soaking your equipment in this solution for at least 10 minutes to ensure that all microbial agents are killed.

Soaking in either a 1-to-5 solution of chlorine bleach or a full-strength Lysol or Pine-Sol brought the most consistent protection, as shown in tests conducted by UGA.  Just dipping the blade quickly often did not disinfect properly.  Chlorine bleach generally did a better job for quick dips, although none of the disinfectants proved 100% effective when using quick dips.  So soaking is recommended in all cases.  Tools have sometimes microscopic scratches that can contain air bubbles, which will prevent contact with the solution.  Soaking overnight is most effective.

Although chlorine bleach is the least expensive and generally most effective disinfectant, bleach does corrode tools when used frequently.  It also can splash up and ruin clothes. Lysol caused the least damage to clothes and tools.”

Tom Carlson, owner of this blog and of HostasDirect and IDealGardenMarker adds, “If you leave your tools in these solutions too long you will get corrosion, and possibly lots of corrosion.   So, the trick is to soak as long as needed but not much more.    Then, wash the tools with water and wipe it dry or let it air dry.   Plain water will rust tools very fast as well.


 

Foliar nematodes can ruin your hostas

Are Foliar Nematodes (Aphelenchoides fragariae) ruining your Hostas?

These pervasive microscopic worms can greatly disfigure a hosta.   Here is a short summary.

Foliar nematodes create brown streaks in your hosta leaves.   When these symptoms appear depends on your growing zone.  (It’s usually August in Minnesota.)  Although they may live in your hosta year round, the symptoms appear when these microscopic worms have amassed a large enough quantity in your hostas to begin to damage the leaves.  They are prolific egg layers and almost impossible to kill. One of the reasons for the increasing numbers of nematodes the past few years is because a few years ago the toxic chemicals that could kill these annoying worms were outlawed. I have read these same Aphelenchoides fragariae live in about 250 species of plants.

Foliar nematodes can be detected using a magnifying glass.  You can have foliar nematodes for a long time but not even know it as their symptoms have not appeared.  Thus, it is possible to share,  sell or buy infected plants without even knowing it.

What can you do to prevent foliar nematodes?

Purchase our Starter TC  or Advanced Starter disease free hostas.   These plants are grown in tissue culture plant laboratories and are tested for viruses and nematodes before going into mass production.   Most of these plants we sell in our business never even touch the ground.

 

How can foliar nematodes spread?

They travel via water.  If you have hostas infected with foliar nematodes at the top of a slope, you will likely find hostas in the “fall line” below the infected hosta as the nematodes traveled via water to the plants below!

Nematodes can be spread via non-sterilized garden tools that have nematodes on them.   It is important to disinfect all garden tools after each cut.   In particular, every cut if you suspect nematodes are a problem.

I sadly learned from two government disease experts that nematodes can be spread via animals such as pets, rodents, and even birds.   That is another reason why it is close to impossible to guarantee that anything grown in the ground does not have foliar nematodes.   One garden affected can spread foliar nematodes long distances in more ways than we think, so you need to be wary of where you get your plants.

As mentioned, the same foliar nematodes in hostas are appearing on 250 different species of plants now.   Some government plant disease officials told me they felt the many sources of supply of non-regulated plants sold on the internet are causing plant diseases to spread more rapidly.   Again, many people do not even know the nematodes are in their plants.

Pictures and information on foliar nematodes


HostasDirect on Hosta Diseases

The Hosta Library on Nematodes