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In The Garden

By Ralph Purkhiser, Purdue University Master Gardener

In the Garden

Ralph Purkhiser, Purdue University Master Gardener

Winter sowing sites have taken over my computer! Many of the posts tout winter sowing as a new phenomenon is the gardening world. Nothing could be further from the truth. It takes only a few minutes of reading the posts to determine that this very helpful planting method is misunderstood by many.

Winter sowing is not the same as greenhouse or hotbed sowing. Both of those methods are intended to provide a modified environment by using some form of heat, thereby causing seeds to germinate earlier than they would if planted outside. After germination, a heated environment is necessary to keep the young plants alive.

Winter sowing is also not the same as starting plants in your house in a sunny window or under grow lights. These methods are also used to produce transplants for the garden earlier than one could by sowing the seeds directly in the garden in the spring.

Winter sowing will not produce transplants for early planting. Instead, it is meant to provide a more controlled environment and to isolate seedlings that would be sprouting when nature warms enough for germination.

In a natural setting, a plant produces seed at the end of a growing season. As the weather cools in fall and winter, those seeds drop to the ground or are carried by birds and other wildlife. Some of those seeds germinate in the cool weather of autumn, but many seeds lie on the soil until the following spring. The seeds of many plants actually require a cold period before they will germinate. Winter provides that cold period, and when the weather warms in the spring, the seeds germinate and the new plants grow. Of course, not every seed becomes a new plant. Some are eaten my wildlife. Some do not make good contact with the soil and may dry out too much to germinate. Some may be blown onto pavement or other inhospitable environments. Rains may wash away some seeds, and some may be trapped under huge piles of leaves. Winter sowing simply removes many of these variables.

The best candidates for winter sowing are the plants that naturally self-sow. If you purchase seeds for coneflowers, milkweed and other wildflowers, the packet may instruct you to chill the seeds in the refrigerator for several weeks. You may skip that step if you are winter sowing. This scarification will occur naturally, just as it does when the plants drop seeds in a meadow.

Most winter sowing instructions tell you to plant in clear or translucent plastic jugs, such as water jugs. You will need four inches of soil for the best results, so the jug should be cut to leave a container about six inches tall. Cut some drainage holes in the bottom. I find that a hot-glue gun with no glue stick is good for this. Fill the container with about four inches of moistened planting medium. I suggest using a sterile soilless mix, so you do not have to worry about weed seeds. Spread your seeds and cover them at the depth recommended on the packet. Use masking tape to tape the top of the jug back on. If you are doing more than one kind of seed, use a nursery marker to label the jugs. Regular markers may fade.

Place the jug in a sunny location outside. When it warms enough for germination, the tiny plants will grow. You may then need to open the jugs to add water. If the plants touch the top of the jug, you will need to transplant them to the garden or into individual containers.

While this method may be new to some, it is essentially the same as growing in a cold frame. It does not give you plants earlier than direct sowing, but it allows you to control the soil and moisture, and it isolates the plants from others that would be growing in the garden. It is a great way to get more of the plants you need to fill a pollinator garden.

Education/Agriculture

In the Garden

Ralph Purkhiser, Purdue University Master Gardener

The Perennial Plant Association has announced that Pycnantheum muticum is the 2025 Perennial Plant of the Year. The association is a group of plant breeders, nurseries, university researchers and botanical garden staff members who share an interest in perennial plants for the landscape. The selection process allows members to submit nominations for the award, which are narrowed down to four final candidates. The members then vote for the winner. Unlike many “plant of the year” selections, the Perennial Plant of the Year is not one of those new and improved plants. Instead, it is a plant that may be grown in a large area of the country and that has shown garden usefulness over many years. This year’s selection is actually native to a large portion of the country.

Commonly known as clustered mountain mint, it is not a true mint and it is not limited to mountainous areas, but its growth habit is clustered. It is a tough, adaptable plant commonly found in meadows and open woodlands in many areas east of the Rocky Mountains. It is cold hardy in zones 4 through 8. It prefers moist areas, but, once established, will survive hot weather and drought.

If you are a gardener who likes plants to stay in one area, surrounded by mulch, this is not the plant for you. Like true mints, to which it is related, clustered mountain mint will spread by seeds and running roots. Its growth habit is spreading and it is best used to mix with taller plants that have more significant blooms or dark foliage. It is great as a living mulch that will shade out weeds. The minty scent and somewhat fuzzy texture of the foliage also serves to make the plant less palatable to deer and other foragers.

The blooms of clustered mountain mint are nondescript. That is not to say that the blooms are unimportant. When the small white or pink flowers open, small bees and other pollinators will be there to seek the nectar. More noticeable than the blooms are the silvery bracts that surround the actual flowers and persist long after the flowers are gone. The bracts and gray-green foliage serve as a great contrast for plants with burgundy foliage, and make a long-lasting cut foliage when combined with large, bright-colored flowers in vase.

Like many perennials, clustered mountain mint benefits from the Chelsea chop. In fact, this plant may be sheared back after each bloom period to create a more-compact plant and encourage another round of blooms.

I cannot remember having ever seen clustered mountain mint at a local nursery. You are more likely to find it as plugs from a native-plant nursery, or order some seeds and give winter sowing of native seeds a try. Having been selected as the Perennial Plant of the Year, it will likely be more available this year.

I noticed some hellebore buds when I returned home from a short trip on January 1. The next day, I took another walk in the garden and found three hellebores in bloom. This is not unusual, and these were in a clump of Helleborus niger, known as the Christmas rose. They will be fine once the snow melts. The snow acts to insulate garden plants, so just enjoy the beauty it brings to the garden. Stay warm and safe.

In the Garden

Ralph Purkhiser, Purdue University Master Gardener

As we move into a new year, seed and nursery catalogues start to arrive. They are the equivalent to the Sears wishbook for gardeners. However, like the Sears catalogue, seed catalogues are not what they used to be. In this digital age, some companies have ceased printing catalogues. Others send catalogues only on request, with some actually charging for the books. Of course, the seed and nursery companies all have websites, and one can sit at a computer and search for seeds and plants. However, it does not have the feel of sitting in a recliner on a cold, snowy January day, thumbing through the pages of seed catalogues and marking the pages on which must-have plants are featured.

Whether using the electronic forms or printed books, seed and nursery catalogues should come with a warning label—“Perusing these pages may be hazardous to your bank account!” Be sure to check out the shipping costs. Costs vary greatly from company to company, but these added costs may add a lot to the final bill. Also look at the warranty being offered. Some companies will replace plants that do not thrive in your garden; others do not offer warranties on their products.

Also beware of the pictures and “new and improved” labels. Breeders are constantly working to get larger blooms, better disease resistance and expanding planting zones of plants, but catalogues may exaggerate the improvements, and most certainly the colors you see in the books are not the exact colors you can expect to see in the garden. Be especially wary of blue plants. Blue is rare in the plant world, and there are few true blue flowers. The catalogue may have a flower that is royal blue, but do not be disappointed if the blooms are blue violet or some other shade of purple. Also watch for a “substitution” statement, giving the company the right to substitute another plant or seed packet if the one you order is out of stock. It is disappointing to have ordered a special item and receive something unexpected.

Despite the drawbacks, I love looking through the seed catalogues. I will mark plants I find interesting and I enjoy reading the descriptions for new offerings. I have a healthy level of skepticism, so I am not taken in by the descriptions of perfect plants.

After hours and even days of looking through catalogues, comparing the offerings and prices of various companies, I will make a decision on my seed order for the up-coming season. I prefer to buy plants and seeds at local garden centers, but I know that some new plants and specialty seeds are not likely to be available locally. I usually order several varieties of greens, especially my favorite oriental greens. I will order Malabar spinach, more for its vigorous growth and blooms than its value as a food crop. I will also order red okra for both eating and using in flower arrangements. It is hard to find red okra locally.

I rarely order plants. I have been disappointed too many times when I have received tiny specimens that will take years to reach the size of the plant image in the catalogue. I prefer to see the plant before buying it, and I will stop at every greenhouse and garden center I pass when they open in March. I may have to wait a year or two to get the new plants, but if the plant is truly an improvement on the old plants, it will eventually show up locally, and likely in a larger size. If it does not become available locally, it may be because the plant has not performed well in our climate.

The first day when the roads are slick with snow or ice, I will heed the recommendation to stay at home. I will have a fire in the fireplace and a stack of seed catalogues next to my chair. It is the perfect way to spend a winter day.

In the Garden

Ralph Purkhiser, Purdue University Master Gardener

It is Christmas week, and like everyone, I have been busy. Still, I take a little time to walk through the gardens. If for no other reason, it reminds me that there is still a lot going on and the garden can change in a day.

I noticed that some of the spring bulbs have already sprouted. One patch of scilla is nearly three inches tall. That foliage will likely be subject to some freeze burning, but these are tough plants, and I am sure the blooms will come in the spring. One possibility is to spread some mulch over the top of the erupted foliage. The purpose of the mulch is to keep the ground frozen, thus retarding further growth.

It is also a good time to apply mulch around the perennials, trees and shrubs that were planted in the fall. Again, this is to keep the ground cold and reduce the chance of heaving when temperatures fluctuate. Before applying the mulch, press firmly around the root system to ensure there is good contact with the soil. Be sure to leave the crown sticking out to keep from smothering the plant. Do not let the mulch touch the bark of woody plants. The mulch should be about two inches away from the base of a tree or shrub.

Wintery garden walks are also a good time to observe the bones of the garden and make plans for improvements. Take some photographs and spend some winter evenings playing with them. You may use some landscaping software to create the changes you envision, or keep it simple and use paper cutouts to add pergolas, arches and trellises. Place a few boulders in garden beds and add some new pathways. Go ahead and make those pathways with expensive marble slabs, even if you will have to settle for gravel in the final installation. Dreams do not cost much.

Right now, the best time to view the garden is at night. I love the holidays, and although I did not get everything decorated as I had planned, my yard is aglow. The center of things is the true reason for our celebration—my nativity scene. The old blow-mold figurines are beginning to show that they are over thirty years old, and some of the lights do not work, but it still conveys the message of “Peace on Earth and goodwill to all men.” Drive by some evening. Just start out Sandhill Road and you will know when you have reached Sandhill Gardens. It is glowing. I hope you enjoy the show.

In the Garden

Ralph Purkhiser, Purdue University Master Gardener

This is In the Garden column number 900! I can hardly believe I have been doing this so long, but all of those old columns still reside in my computer, so it must be so. I look back at old columns occasionally, and I can see changes in my garden style over the years.

Years ago, the vast majority of my garden space and time was consumed with raising food. My family had always planted a large vegetable garden and sold a lot of produce. Now, I raise most of my vegetables in several raised beds. I have not sold produce for many years, but I raise enough vegetables for myself and some for friends and family. I used to use chemicals in the garden, but, while I am still not one hundred percent organic, I definitely use more organic methods. I am a great proponent of composting and using the resulting “black gold” in my garden. I have researched and tried various composting methods, and have often written about those methods in this column. Still, most of my composting is done in an informal compost pile, which gets turned occasionally. It works for me.

Of course, with so much former vegetable-production acreage out of service, I had to make a decision on what to do with that space. One fairly large area has become my meadow. Once again, I have not followed all of the rules on making a meadow or prairie, but I have created a place where wildflowers thrive and bees, butterflies and other creatures make their home and find food. Once again, I have not been a purist. Some say a true prairie should contain only native plants, but I have witnessed that the native fauna have adapted to feed on many of the plants that escaped from the cultivated gardens of our European immigrant ancestors. I welcome plants like dandelion, chickory, and Queen Anne’s lace into my meadow. I have heard many say that these are invasive, but, while I realize they are naturalized non-native plants, I have not seen them crowd out the native species. Instead, they seem to co-exist with other wildflowers and they add beauty and wildlife food. I doubt I could eradicate them if I tried, especially without using chemicals, which I consider more dangerous than these plants. Still, my favorite flower is the native purple coneflower, and I still believe it should replace the non-native peony as the Indiana state flower.

Ornamentals have also been given a much larger share of the space at Sandhill Gardens. Again, I have a mixture of native and exotic species. I am aware of the dangers of invasive species and have been weeding out true invasives, but I cannot bring myself to limit myself to native plants only. I love the peonies my grandmother planted a century ago, and the daffodils that have grown here for decades and the new ones I have added.

I have also added many more shrubs of various sizes. As I age, I find that shrubs can cover a lot more space than perennials and take a lot less work. I have also added several trees, some of which have matured to large specimens. That means a lot more shade. I have come to love the shade gardens the most of all. Gardening in the shade is a lot more comfortable than spending hours weeding row crops.

I have also changed many of my gardening methods. Some of the changes have been forced upon me because of age and physical limitations. I have found ergonomic tools that make many jobs easier. I no longer own a roto-tiller. I have found more success just top-dressing beds with compost and allowing the worms to work that organic matter into the soil. I use raised beds of various heights, both for food production and in ornamental areas.

The way readers see my column has also changed. Many of the publications that carried the column years ago no longer exist, or have changed considerably. More readers now see the column in on-line publications. Still, I receive enough feedback to know that the column makes a difference for gardeners in southern Indiana, so I continue to write. It is, however, still true that the column is written as a way to generate volunteer hours needed for the Purdue Master Gardener program, and I thank you for helping me climb the program ladder. I do not know what the future holds, but, for now, I continue to garden and write.