“With which of your products does one prep the soil for winter crops in a mini greenhouse, type Cold Frame Mini Green House by Juwel (I just got one)? It will face South-East. Any experience growing with this method? Any easy crop recommendations?” Question from Judy of Yarmouth Port, Massachusetts
Answer: Thank you for your questions. I have gardened in a cold frame and observed successful and unsuccessful cold-frame gardening. In your northern garden, I would place the cold frame in a sunny south-facing spot close to your home. The reflective heat from the house will provide some winter protection, and the warm sun will help heat the cold frame. If you can, I would also recommend sinking the cold frame a few inches below the soil level, even though I see that the frame you have purchased has clear sides. Really good cold frames are set below the soil level to better hold heat in winter. On unexpectedly hot fall or winter days, be sure to prop the top open to keep the internal temperature from getting too hot.
Cold-Frame Soil
As far as soil, I would amend your ground soil at the base of the frame with good compost, like Black Gold Garden Compost Blend, at a 1:2 ratio of soil to mulch. The addition of earthworm castings would also be enriching. The lighter and more fertile your soil, the better your veggies will grow. Adding a layer of compost as a protective mulch would also be helpful. (Click here to learn more about creating the best soil for raised beds.)
Cold-Frame Vegetables
It is essential to grow cool-season, frost-resistant crops. These are largely winter greens and root crops. The greens that I recommend include mâche, kale, lettuce, and spinach. The best root crops include winter carrots, radishes, and turnips. Parsley and chives are good herbs to try. (Click the following link to learn more about growing winter root crops and click this link to learn more about growing cool-season greens.)
As the season grows cooler, the old flower heads of tall sedums darken. (Image by Jessie Keith)
In the fall, many plants begin to wither and fade away quietly from the garden. Some pass so gently into dormancy that we often don’t notice their departures. Happily, there are other high-spirited exceptions that refuse to exit meekly. Instead, they fire up their flowers, fruits, and foliage to keep the garden showy late into the year. These individuals—perennials, shrubs, and trees–wait until the end of the growing season to put on flamboyant autumn displays, going into winter in a blaze of glory.
Colorful Garden Plants for Autumn
Bluestars
Fine-leaved Hubricht’s bluestar has beautiful fall color. (Image by Jessie Keith)
The bushy eastern bluestar (Amsoniatabernaemontana, USDA Hardiness Zones 4-9) and fine-leaved Hubricht’s bluestar (T. hubrichtii, Zones 5-9) are quiet individuals in the spring and summer garden. They produce spring flowers of the gentlest blue and feathery mounds of summer foliage in an unobtrusive Garden-of-Eden green. Then, one fine autumn day these retiring beauties undergo a stunning metamorphosis. Suddenly, bluestar’s green foliage radiates a dazzling, show-stopping golden orange. There is a miniature, spreading, fine-leaved form, called ‘Georgia Pancake’ (Amsoniaciliata var. filifolia ‘Georgia Pancake’, Zones 4-9) that reaches only about 6 inches tall and spreads to 2 feet wide and is equally attractive in fall.
Deer resistant bluestars grow to a bushy 3 feet tall by 4 feet wide when grown in average soil and full to partial sun. At planting time give them a boost by amending their soil with Black Gold Garden Soil, which has a little added fertilizer to get plants off to a great start.
Tall Sedum
Sedum ‘Autumn Joy’ is a perennial fall favorite.
In spring, perennial Autumn Joy sedum (Sedum telephium ‘Autumn Joy’, zones 3-8) becomes a neat, round, 18-inch mound of succulent, pale green leaves. In mid to late summer, stems of domed, pink flower heads cover the clump and are bee and butterfly magnets. As the season progresses, the color of the aging flowerheads deepen until in late fall when they radiate deep rose-red. After frost, the flowers turn rich copper. Another exceptional tall sedum is the knock-your-socks-off ‘Mr. Goodbud‘ (Sedum telephium ‘Mr. Goodbud’, zones 4-9), an award-winner that is slightly shorter and has brilliant domed flower heads of purplish-pink.
Tall sedums prefer full sun. As long as their soil is well-drained and holds average moisture, they will grow well.
Little Bluestem
Little bluestem Blue Heaven™ turns brilliant shades in fall. (Image by Proven Winners)
Sun-loving little bluestem Blue Heaven™ (Schizachyrium scoparium Blue Heaven™ ‘MinnblueA’, zones 3-9) grows into an upright, 2-4-foot clump with soft gray blades that are streaked with sky blue and tipped with dusty purple. This well-behaved grass maintains its discrete coloring until the days begin to shorten. Then, its quiet hues flame a fiery burgundy-red that turn orange-brown as they dry.
Blue Heaven little bluestem prefers full sun and grows best in average, well-drained soil. In the heat of summer, it will take drought.
American Beautyberry
Beautyberry tree or American beautyberry (Callicarpa americana) transition of unripe green to ripe purple or Beautyberry Shrub with Purple berries
Our native (Callicarpa americana, zones 6-9) is a fast-growing shrub that reaches 3-6 feet tall and wide. Its shy, lavender or white summer flowers usually go unnoticed. It isn’t until autumn that this native lives up to its name. It becomes a showy beauty when the insignificant flowers ripen into glowing purple berries that encircle the stems like jeweled bracelets. A bird favorite, beautyberry shows its finest when grown in full sun to partial shade and moister garden soil amended with Black Gold Canadian Sphagnum Peat Moss. As long as its berries are not snapped up by birds, they remain attractive until early winter.
Staghorn Sumac
Sumac Tiger Eyes turns brilliant shades in fall.
Sumac Tiger Eyes (Rhus typhina Tiger Eyes® ‘Bailtiger’, zones 4-8) never suffers a dull day during the growing season. In spring, finely cut, bright golden-yellow leaves stand against the pink stems of this shrub and make it a colorful standout from the moment its leaves first emerge. It stays colorful into summer, though the leaves may revert to green. Then, in fall, the foliage of Tiger Eyes® converts to riveting oranges and scarlets, putting on a display that is an extravaganza of dazzling, brilliant color. It may also produce spires of deep reddish-orange fruits that will stay attractive into winter.
This fast-growing North American small tree quickly reaches 4-6 feet tall and wide in full to partial sun. It is drought-resistant and tolerates poorer soils but still appreciates a soil amendment, like peat moss, at planting time.
Sweetspire
Sweetspire turns shades of purple, orange, yellow, and red in fall. (Image by SB_Johnny)
Little Henry dwarf sweetspire (Itea virginica ‘Little Henry’, zones 5-9) is a great all-purpose shrub that thrives in the sun or shade and looks fine massed in a border or as a foundation plant. It can even naturalize in a woodland. This petite, 3-4-foot-tall shrub tolerates periods of drought as well as moist soil.
Drooping, elongated clusters of fragrant, ivory flowers blanket the plant in early summer, attracting hordes of butterflies. The clean, shiny, green foliage is free from serious disease and insect problems and unappealing to deer. In fall, Little Henry’s shiny green leaves turn shades of flamboyant orange before deepening to glowing garnet-red. Its color is most vibrant when the shrubs are grown in sunnier locations.
Spectacular garden plants that look good through summer, but also to put on vivid displays in fall, are doubly cherished. They extend a garden’s showy season by going out in a blaze of glory.
“My heirloom tomato plant is growing beautifully. However, it has not one tomato on it, while another bush, under same growing conditions, is more prolific though it still does not have ample tomatoes. Is there something I am doing/not doing correctly? During the long summer days the beds do get over 6 hours of sun a day, as the days are getting shorter they are down to about 51/2 right now. I use no chemical pesticides. I only have two tomato plants and check them daily.” Question of Ann Marie of Holbrook, New York
Answer: Several things can keep otherwise healthy looking tomato plants from producing ample good fruit. These are 1) imbalanced nutrition and 2) too little sunlight. Tomatoes are heavy feeders that need high nutrition, regular watering, and at least eight hours of direct sunlight for good fruit production. All of these are necessities.
Fertilizer is easy. Choose a fertilizer formulated for tomatoes and feed your plants regularly, as recommended on the package. Adding additional bone meal is also helpful in reducing the chance of blossom end rot, a common nutrient deficiency of tomatoes.
Sunlight may not be as easy to provide, depending on your yard, but eight or more hours are needed for fruit-producing vegetables, like tomatoes, peppers, cucumbers, and squash. More is even better. I plant my veggies where they can get all-day sun for maximum output.
If you plant only a couple of tomatoes, try growing them in large containers and moving them to a sunnier part of the yard. This will enable to provide them with more sun and better control their soil, nutrients, and water. Black Gold Natural & Organic Potting Mix is a great potting mix choice. Please watch the video below to learn more about how to grow great tomatoes in containers.
“I live in SW, Florida – what is the best time of year for growing vegetables? Question from Colleen of Englewood, Florida
Answer: I see that your summers are sweltering, humid, long, and can be cloudy while your winters are short, cool, and sunnier. What you grow in these times depends on the crop and season.
In the “cooler” winter months, you can grow root and cole crops. Late winter and fall are good times to start many warm-season vegetables that don’t thrive in raging heat. In high summer, grow super heat-loving vegetables, like Southeast Asian eggplant and okra.
Here are some crops that I would recommend for each season:
Male squash bee (Peponapis pruinosa). (Photo courtesy of USDA-ARS Bee Biology and Systematics Lab)
“What is the pollinator for summer squash? I stopped trying to grow them after getting zero fruits last summer!” Question from Robin of Warner, New Hampshire
Answer: It is frustrating when squash do not set fruits. There can be several reasons why, but the primary reason is lack of pollination. The main pollinators are bees or all types, but squash (Cucurbita spp.) are native American plants, so they have unique native American bees specialized for pollinating them. Squash bees are small and come in two groups (Peponapis species and Xenoglossa species). They are solitary, meaning that they do not create hives, and they ONLY pollinate squash.
Keeping a Yard for Bees
Your squash should be enough to encourage squash bees, but if they are not abundant in your area, then you will need to rely on other bees to do the job. One way to encourage more bees to visit your vegetable garden is to plant swaths of garden flowers for bees nearby. Surrounding your garden with flowers is a great method. Bees love easy flowers like zinnias, cosmos, marigolds, sunflowers, and black-eyed-Susans. (Watch the video below to learn more about flowers for bees.)
It is also essential to refrain from using toxic pesticides in your garden. These kill bees that happen to land on a sprayed spot. Harsh chemicals in the garden aren’t worth it.
Sometimes fertilizer imbalance can contribute to poor production. Be sure to feed your squash with a quality fertilizer formulated for vegetables. Low light can also cause poor fruit set, so give your plants full-day sun. For additional information, I recommend that you read this article: Why Aren’t My Squash Bearing Fruit and Do They Have Borers?
Happy Gardening!
Jessie Keith
Black Gold Horticulturist
Here’s a shot of my no-till garden three years after its creation.
“When creating no-till garden beds, do you think it’s best to till once and never again, or just use a never till method?” Question from Anthony of Bentonville, Arkansas
Answer: There are lots of benefits to going no-till with vegetable beds, especially when it comes to weed and weed seed control and the encouragement of soil beneficials. For me, creating a good no-till garden started with a big investment. I dug deep, enriched my beds to the hilt, and lifted and bermed my planting areas. (Lifting soil is especially important if your garden’s topography is low.)
Here’s my five-step method for starting a no-till garden.
Till deeply: Creating a good vegetable bed is all about adding lofty tilth and good fertility for extra drainage and deep rooting. In my opinion, you cannot accomplish this without initial tilling. For excellent no-till bed longevity, you have to start by lifting and aerating your soil as deeply as possible.
Double dig: Move the lofty tilled topsoil aside and double dig areas that you plan to plant. This is easier if your beds are on the smaller end, but at bare minimum, double dig the areas where you plan to grow root crops. (Click here to read more about double digging.)
Amend all of your backfill: Amendments rich in organic matter and microbes are essential for the longterm health of your garden. Work as much good stuff, like Black Gold compost, earthworm castings, peat moss, and even composted manure, into your backfill as possible and till it in.
Define pathways, fill, and berm: If you have a large or relatively large garden space, it’s nice to establish paths for easy garden access and harvest. Most gardeners choose a row or block design. I always like my pathways to stand a bit lower than my beds to encourage deep rooting, so I berm up fill in the bed areas.
Cover: As a final step, I cover my walkways with black & white newspaper or non-waxed corrugated cardboard and cover the paper with a thick layer of seed-free grass clippings, straw, or even pine straw. You can even plant nitrogen-fixing clover in the walkways. Then I add a thick layer of compost along the top of the beds to detur weeds.
Each year, I clean up and refresh the walkways and add fresh compost as a mulch. Invest in your no-till garden like this in the beginning, and you will be wowed by the results.
“I have a large, 1/2 whiskey barrel in my flower garden, planted with various types of marigolds. Since Mother’s Day, when I planted them, I’ve fertilized them every two weeks. I am faithful about deadheading them as needed, on a daily basis. I water as needed. They are just glorious this year! 1) Should I continue to fertilize them? How long can I expect them to last? Thanks so much!” Question from Diane of Newark, Ohio
Answer: I love marigolds, too. They are heat tolerant, tough, beautiful, and so easy to grow. It sounds like you are doing everything right! Continue to fertilize them until mid-September, and they will keep blooming until the first frost of autumn. Late-season bees and butterflies that gather pollen and nectar towards the end of the season will thank you.
If you like to save seed, I would also suggest letting a few blooms go to seed, starting in late September. Once the plants have all succumbed to frost, remove the mature seedheads and pull the withered plants from your whisky barrel. Through winter, store the seeds in a paper bag kept in a cool, dry place. Then the following April, refresh the barrel’s potting soil (Black Gold Natural & Organic Potting Mix is excellent) and sprinkle the seeds on the surface. Keep the soil moist, and they should start sprouting once the soil warms. I like this method because it’s free and effortless. Open-pollinated plants typically don’t look just like their parents, but the variation in the flowers from year to year is a fun surprise.
“I can never seem to grow zucchini right. Is there a type of soil that would be best for this?” Question from Amy of Oil City, Pennsylvania
Answer: We have gotten this question a lot, both with respect to zucchini and summer squash (both are the same–one is just green and elongated.). I have provided links to several of these Ask a Garden Expert answers. But, to directly answer your question with respect to soil, provide your zucchini with soil that is well-drained and rich in organic matter. It grows best in a near-neutral pH and requires a fertilizer for fruiting vegetables. You will also need to grow it in full, all-day sunshine.
Ask a Garden Expert Answers For Zucchini and Summer Squash Growing
“What succulents will grow outdoors in Colorado ZIP 80021, Growing Zone 6?” Question from Joe of Westminster, Colorado.
Answer: I love hardy succulents and have written about them extensively because they are beautiful and easy to grow in many areas of the country, with good bed prep. I see that Westminster has an average rainfall of 17-inches per year, a good bit lower than the 38-inch-per-year national average, so you live in dry country. Thankfully, there are loads of hardy cacti and succulents beautifully adapted to your Zone 6 Cold Hardiness. Here is a very small sample of my favorites.
Agave
Parry’s Agave (Agave parryi): This amazingly cold-hardy agave can survive winter cold to Zone 4, as long as the winters remain quite dry. It is compact and has tough, silvery foliage with sharp black tips. Plant it in very well-drained soil.
Havard’s Agave (Agave havardiana): This super bold agave forms very large rosettes of grey-green foliage and is hardy to Zone 5, where winters are dry.
Claret Cup Cactus (Echinocereus triglochidiatus): This super hardy hedgehog cactus has spectacular orange-red flowers, and plants will survive to Zone 5 in a raised rock garden. It is a real beauty that’s well worth growing.
Fragile Pricklypear (Opuntia fragilis): This low, creeping pricklypear is an alpine native of Colorado and bears lovely pale yellow flowers in late spring.
Sedums and Sempervivums
There are so many amazing sedums and hens-and-chicks to grow it is hard to know where to start, but here are a few beautiful varieties of various sizes to consider.
Cliff Stonecrop (Sedumcauticola): This hardy (Zone 4) low-growing sedum has dusty purple foliage and deep rosy pink flower clusters in summer.
I cannot choose a single variety of hens-n-chicks, so I suggest you view this expansive list of them for sale at Mountain Crest Gardens. All are hardy.
It’s important to mention that you have a very good source for cold-hardy cacti and succulents close to you called Cold Hardy Cactus. It offers an excellent list of beautiful and unusual succulents well adapted to the drier regions of Colorado.
Clean, tidy garden edges frame a garden and elevate simple beds and landscapes. Clean lines show off gardens and are well worth the small effort. This video covers cutting curved garden edges. For straight edges, it can help to tie a line from one edge of the garden to the other and mark the straight line along the ground with chalk marking paint. This will help guide straight cuts.
