Seasonal Garden ideas

Winter Sowing: DEcember is a good time to start

Growing plants from seed is a fun and inexpensive way to add more native plants to your gardens. Many native seeds need a period of "cold stratification" to break their dormancy and allow them to germinate in the spring. Their dormancy period is an evolutionary adaptation to prevent seeds from germinating in the fall, only to die when the winter arrives. One way to cold stratify is to use your refrigerator to mimic outdoor winter conditions; learn how here. An alternative and often simpler way is to “winter sow” the seeds in small pots or containers and place them outside where they are exposed to snow and rain in the winter, breaking their dormancy naturally.

If you have collected seeds in the fall, now is a good time to get started. But if you are too busy preparing for the holidays right now, don’t worry. Winter sowing can still be done in January and even in early February. If you don’t have seeds, you may still be able to get some from a friend’s garden, assuming that the birds did not eat them already. Alternatively, you can check with the Wild Seed Project in Maine for availability.

Winter sowing can be done using many types of containers such as milk and water jugs, take-out food containers, and other large plastic containers with deep bottoms and transparent tops. Water jugs are particularly well-suited because the height inside gives the plants room to grow before having to be moved into the ground or transplanted to individual pots. Also, most water jugs are made of translucent rather than clear plastic that moderates the temperature inside the jug and prevents the scorching of the seedlings on a sunny day.

Mini-greenhouse materials and supplies: water jug, potting soil, knife, duct tape, marker, plant label, seeds. Note: Don't cut through the jug handle; it is your hinge.

The method described below turns the jugs into mini-greenhouses that protect the seeds, allows early germination, and gives your plants a head start for the spring. Here are the steps:

  • Start with clean, sanitized 1-gallon milk or water jugs.

  • Poke holes in the bottom of the jugs for drainage using a sharp knife or a screwdriver.

  • Using a utility knife or scissors, cut around the jug circumference just below the handle, but leave the handle attached to serve as a hinge. The bottom part should be deep enough to hold 2-3 inches of potting mix.

  • Add potting mix to the bottom section of the jug. For good drainage, be sure to use a potting mix rather than potting soil. Avoid seed starting mixes or anything with a lot of peat moss.

  • Add the seeds. Some seeds require light to germinate and should not be covered by potting mix. A light sprinkling of fine sand may be helpful to keep the seeds in place. Other seeds germinate without light and should be covered by a light layer of potting mix. Larger seeds should be planted slightly deeper than smaller seeds.

  • Using a spray bottle, water the newly sown seeds to gently soak the potting mix down at least an inch. It can be hard to distinguish species of very newly emerged seedlings, so be sure to label each jug by placing a plant label inside before closing it up. You should also label the species on the duct tape that you use to close up the jug along the line where you cut it open earlier.

  • Once the seeds are sown and the jugs are labeled and closed, it is time to put them outside in a place where they are exposed to rain, snow, and sun. A place with partial sun light under a tree or behind a shrub may be best to moderate the temperature inside the jugs and prevent pre-mature germination as spring approaches. Occasional watering may be needed if the winter is unusually dry.

Due to the warmer temperatures inside the jugs, the seeds will germinate earlier and result in larger early spring plants than if the seeds were sowed directly into the ground. No hardening of the plants is needed because the plants have already been exposed to the outdoor temperatures all along. Here's a video link with a good description and illustration of winter sowing. Good written instructions are also offered by Penn State Extension and the Wild Seed Project.

Spring: An invasive wake-up

Springtime is such a delight—flowers and leaves erupt from plants’ long winter slumber. Color and scents catch our senses everywhere we turn. The birds sing out their delightful spring songs as well.

Yet, we also watch with dismay as a regular crop of invasive plants reappear in our gardens each year, old foes we battled last year. Invasive plants are one of the greatest threats to the nature in Massachusetts. It is an ongoing effort, carving out space for our native plants against the pressures invasive species exert, and early spring is a good time for physical control methods before they really get growing for the season.

To remove such plants, we recommend hand-pulling, cutting, and mowing whenever possible. Use of toxic chemicals can be very damaging to the surrounding environment, including plants and wildlife, and should therefore be avoided whenever possible. Below are control recommendations for five species we find to be common and very aggressive in gardens here in Lexington.

Recommendations for Removal and/or Control:


Small plants can be hand-pulled but the entire plant should be removed including the roots. For climbing vines, you first cut the vines as close to the ground as possible before making a second cut at eye level or above. The cutting should be done before spring arrives to prevent new growth of the vine from shading and weakening the host plant. Unless the root is removed, the cutting may have to be repeated the following year since new shoots often emerge from the base of the original vine. However, repeated cuttings over several growing seasons will exhaust the root system and eventually kill the plant

Garlic mustard

Pulling individual plants by hand is the simplest way to manage garlic mustard. When pulling the plants it is important to include the roots since they can produce additional stems if left in the ground. All plant material should be collected and removed from the site as seed ripening continues even after the plants are pulled. The seeds remain viable in the soil for up to 10 years and repeated annual hand pulling will be needed until the seed bank is exhausted.

Japanese knotweed

Japanese knotweed is a highly invasive plant with roots that can penetrate up to 6 feet deep and up to 65 feet wide. Getting rid of the plant is a challenge and will require repeated efforts over many seasons. Non-herbicide approaches for removing the plant include: Repeated cutting throughout the summer, starting when the plant is no more than one foot tall; smothering the plant with tarp in the spring; and digging at any time (but especially before smothering). Using multiple removal methods will increase your chances of success.

Burning Bush

Burning bush outcompetes native species that birds and other wildlife need for food and shelter. Young plants of burning bush can be pulled out of the ground by hand. Seedlings are especially easy to spot in the fall when their color is bright red. For larger plants, the branches of the plant can be cut and the roots dug up. A shovel and a hand clipper to chop off the roots are useful tools for uprooting the plant. When removed from a garden, it is important to replace the plant with some native shrub or tree that will provide more value to wildlife.

Multiflora rose

Hand-pulling of individual plants along with the roots can be effective when the plants are small and grow in isolation. Cutting is appropriate for smaller populations of plants. The stems should be cut down to the ground and the roots dug up, if possible. Repeated cutting of the stems alone will control the spread of the plant, but will not kill them. For areas with larger stands of multiflora rose, mowing a few times per year can provide partial control by restricting top growth and spread.

bittersweet's distinctive orange roots

A lush stand of knotweed chokes out native plants.

AuTUMN: Putting our Gardens to bed

Fall is the time of year many of us focus on our labor-intensive “clean up” activities including leaf raking, cutting back flowering plants in our garden beds, and generally giving a tidy appearance to our yards before the ground freezes and winter sets in. However, all of this hard work actually reduces the ecological health of our gardens. Easing off a bit in key areas and allowing more natural processes can help improve soil and plant health while also providing needed shelter and food for birds and insects. Plus, all the time you save on fall chores means more time you can spend relaxing and enjoying your backyard as the plants and animals reabsorb nature’s strength in preparation for their springtime renaissance.

Leaving fallen leaves and spent flower heads are two very easy and helpful changes you can make. And this doesn’t have to be all or nothing! Try a couple of the suggestions below if doing them all feels like it would leave your yard too untidy this year.

Fallen leaves = free mulch! Or perhaps you can say to yourself, “Leave the Leaves!” Leave them on your grass as much as you can bear to. Leaf pieces will decompose to improve your soil for next year’s growth.

Leaf litter for wildlife. Leaf litter, that layer of new-fallen leaves this year above the soil itself, provides important shelter for insects and salamanders, which themselves provide food for birds. Fireflies live in leaf litter. No litter, no magical lights next summer.

Spent flower heads and stalks: leave them standing. Use clippers to remove diseased plant parts, but leave the rest until spring. Spent flower heads provide seed for birds to eat in fall and winter while food is scarce. Insects overwinter both within parts of the plants or in the soil around the roots--vital shelter for them during the cold of winter. Additionally, stalks can enliven your garden with a ghostly presence over the winter.

Eco Landscaping Tips:

  • If leaves on your grass look untidy and you want to remove them, you can rake them into flower beds where they can provide protective insulation for perennial plants and water conservation benefits just like wood chip mulch. You can also use them as collars for bases of trees. And if you have kids that desperately need to get some outside time, there’s the added benefit of letting them play in a pile of crisp fall leaves. And in a gift that keeps giving, fall leaf mulch can actually lock in moisture through the next summer which is important for our gardens when water use restrictions kick in.

  • Don’t use a leaf blower; most bees live in the top layer of soil and leaf blowers destroy this habitat.

  • Stop applying chemical fertilizers. The benefit of the nutrient-rich leaf litter means you can also save money in addition to saving your time.

Interested in reading more on this topic?

From Audubon: To Help Birds This Winter, Go Easy on Fall Yard Work

Doug Tallamy’s ecological thoughts on fall cleanup

In March, snowdrops have no trouble emerging through the leaves and stems leftover from last year.

The first in a series of photos tracking a perennial flower bed through the seasons. Check back in coming months to see how the flowers have emerged.

Second in series: early spring flowers emerging through last year's leaf litter mulch.

Third in series: by late spring, coneflower leaves have grown in to hide the leaves.

Spring Clean up: Less is More

Mother Nature doesn't do much in terms of spring clean-up and you don’t have to either. The key fact about spring clean-up is: butterflies, bees, ladybug beetles, fireflies and other beneficial insects overwinter (in one form or other) in leaf litter and plant stems, or rest in the top inches of soil. The more you remove, the fewer insects remain. It's best is to just leave the leaves where they are. You will find they provide free mulch and eventually disappear. You will have more earthworms (indicators and manufacturers of good soil) wherever you have leaf debris.

If you must remove leaves, use them as natural mulch for shrubs and perennials. Use a rake. Leaf blowers, whether gas or electric, destroy the insect habitat we are trying to protect. Create a brush pile of leaves and fallen branches somewhere unobtrusive. What about stems on perennial plants? Stems provide shelter for some bees and other beneficial insects that have spent the winter inside them. Best is to leave them until the temperatures are consistently in the 50’s, when the insects will have emerged. If you must remove these stems before then, add them to your brush pile too, so the insects can emerge in April and May. They will bring in hungry bird visitors for you to enjoy. Over the years, I have noticed that brush piles in full sun attract more birds than brush piles under trees. Loosely stacked brush piles also provide shelter for ground-dwelling birds.

Mulching around shrubs and trees. Newly planted trees can benefit from a ring of mulch for retaining moisture and preventing competition with grass. Make sure mulch is at least six to twelve inches away from the trunk because mulch encourages bark rot. Two inches deep is plenty. Deeper than that can prevent oxygen from getting to the roots which might compensate by growing up into the mulch. Raked leaves are just as effective as wood chips. For perennial beds, put mulch down as late as possible so that the ground has a chance to warm up. Late May is a good time around here. If you saved your leaves from fall, you might manage with little or no additional mulch.

Mowing and watering your grass. Watering frequently might seem like the best way to keep a luscious lawn of grass, but your grass will actually put down deeper roots and be more resilient to drought if you water it less frequently—such as twice a week for 30-40 minutes. Watering more often encourages fungus, mildew, and shallow root growth. Watering your lawn early (5-9AM) ensures the water is absorbed into the soil but doesn’t linger on the grass blades. Taller grass blades encourage root growth and make

the grass plants more drought-resistant, so consider raising your mower’s blade to 3-4 inches.

Herbicides and pesticides kill plants, earthworms, and insects. Consider allowing dandelions back into your lawn. A generation ago, dandelions and clover were common parts of lawns. After World War Two, chemical manufacturers created a new market for their products in suburban lawns through advertising campaigns targeted on eliminating our dandelions. Kids love dandelions and bees rely on them as some of the earliest spring flowers. Let them back in! The rest of the food web will follow.

Winter: Dreaming & PLanning

For many gardeners, mid-winter brings mixed emotions. We're itching for spring, for sunny days and warm weather when we can put our hands back into the soil, plant seeds, watch perennials re-emerge from the ground, and begin the cycle of our gardens anew. But we can also cherish cold winter days for what we can do now: dream and plan! In this dreaming stage, when everything seems possible, we consider what to do differently this year, what new plants to try, or what beds to renovate. Who hasn't enjoyed sitting with a cup of coffee or tea, browsing the seed and plant catalogs, calculating what you have space for and what you can afford, and struggling to be realistic when everything looks so good?

If you're planning to buy seeds this year, try to buy them soonthe pandemic has heightened interest in gardening, so seeds and plants may be harder to find this spring. See our Where to Buy Plants page to get started.

Winter isn't only for planning and seed buying, though. It is also an important time for starting many native plant species from seed. Unlike vegetables and annual flowers we sow in the spring, the seeds of many native plants require an extended period of cold"cold stratification" it's calledbefore they'll germinate, an adaptation to ensure they don't germinate in the fall or a mid-winter thaw. They can be sown directly into the garden or in pots outdoors for later transplant. You can stratify seeds in your refrigerator too. There's information available on how to do this. Both the Wild Seed Project and Prairie Moon Nursery offer guidance, as does a recent article in the Ecological Landscaping Alliance newsletter.

So settle down near the fire with a hot cup of coffee and your laptop (or hard-copy catalogs for the old-fashioned among us) and let your mind drift to the possibilities.