“I have some large compost bins, which produce a lot of compost. Can I plant things in pure compost, or do I need some “dirt” with inorganic materials for the best results? How much inorganic material do I need?” Question from Naomi or Oakdale, California
Answer: Congratulations on your composting success! Compost is one of the best garden amendments available. You can plant in straight compost, but I suggest incorporating it into your sandy garden soil or mixing it with other additives if you want to use it for container plantings.
Compost as a Garden Amendment
When using compost to fortify gardens, incorporate it evenly into your natural soil. Add it liberally if your soil is of very poor quality–especially if you want to grow crops that need fertile soil, like fruits and vegetables. You might also consider building raised beds to make the most of your compost bounty.
Compost as a Potting Mix Additive
If you plan to use your compost for container plantings, include other additives to encourage better root growth in the long term. These include Black Gold Canadian Sphagnum Peat Moss, perlite, and vermiculite. The peat moss with lighten the mix and give it more structure and porosity, while the perlite will help increase drainage. Vermiculite holds water, adds porosity, and holds and distributes nutrients. A well-rounded potting mix would include 40% compost, 30% peat moss, 20% perlite, and 10% vermiculite.
“When is the best time to trim tropical Hibiscus?” Question from Jane of Tampa, Florida
Answer: You can prune these evergreen tropicals at any time to manage plant size, encourage denser growth, and induce more flowering, but pruning is best done in late winter when they are blooming very little.
These tropical Chinese shrubs flower on new wood, and pruning encourages the development of new wood, so it’s a great way to get them to bloom more. Here are five good hibiscus-pruning tips.
Late winter is generally a good time to prune, but wait until the weather is sure to be consistently warm.
Use clean, sharp pruning shears.
Make 1/4-inch angled cuts above the leaf joints (the angle’s point should be towards the leaf joint).
Remove sprawling, unruly branches that ruin the plant’s bushy shape.
Refrain from pruning again until the following year unless your shrubs become too overgrown.
Just be sure to refrain from pruning when your hibiscus are in full flower.
“I planted garlic bulbs for the first time and chose the hardneck variety ‘Music’. I understand that they will be fully mature around the first of August. Where is a good place to cure the bulbs for the duration? I live in a USDA Hardiness Zone 6 area.” Question from Belinda of Fort Wayne, Indiana
Answer: I have actually grown ‘Music’ garlic with great success. It’s a hardneck garlic, which means it has hard “necks” above the bulbs that keep them from being braided, unlike softneck garlic. Hardnecks are also more cold hardy and have fewer, larger cloves than softnecks. ‘Music’ is also a porcelain garlic, which means thin, white, satiny skins surround the extra-large cloves.
Time to maturity depends on the garlic variety and growing location. ‘Music’ is an early to midseason variety. In Indiana, I would expect it to be ready for harvest sometime in July.
In spring, your garlic plants will emerge and leaf up. By summer, each will have tall, upright, oniony leaves and produce a heron-shaped stem and bud; remove the stems and bulbs as they appear, or they’ll deplete the cloves below of energy. But, don’t throw them the stems away. They taste great stir-fried or sautéed.
Dig up the garlic bulbs when the leaves have declined significantly and start to turn brown. Wipe the bulbs clean of dirt, and hang them to dry for a week or two. ‘Music’ is an unusually good keeper for a hardneck. Count on its bulbs to keep for up to several months, if properly stored in a cool, dark place. (Click here for more tips on how to grow garlic.)
“I’m looking for asparagus that will grow in USDA Hardiness Zone 10b.” Question from Lori of Venice, Florida
Answer: Asparagus generally survives in USDA Hardiness Zones 3-8 and requires a winter dormancy period to successfully grow and produce spears. In northern regions, plants can produce for up to 30 years, but they don’t tend to fare well down south where winters are warmer.
With that said, some varieties will produce spears in Central Florida, but they generally stay productive for just three to five years. One of the best of these varieties is the California-bred ‘UC-157’. (Click here for a good source.) This is the asparagus that you want to grow in your part of the world. To get special planting instructions for Central-Florida gardeners, visit the University of Florida’s page on the subject (click here to view).
“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.
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.)
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.)
“We live in Miami and planted gladiolus bulbs this spring. They bloomed beautifully! How are we supposed to cut them, so they bloom next spring? Should we dig them up or just cut the leaves?” Question from Brenda of Miami Florida
Answer: Gladiolus hybrids will thrive year-round as perennials in your Miami garden (USDA Hardiness Zone 10), so they don’t need to be dug up in fall. Cut back the foliage as it starts to turn yellow. The plants will experience some dormancy before putting forth new foliage and then flowers.
Gladiolus species are native to Africa, Southern Europe, the Middle East, and Asia and garden hybrids are mixes of quite a few species from these areas. Where native, gladiolus undergo either a cold-season or dry-season dormant period. Because you have very little seasonal cold, the main thing that will kill your glads is excessive soil moisture during dormancy. So, make sure that their soil is fast draining and very porous. Plant them in light soil that is raised and well amended with organic matter, such as Black Gold Peat Moss. You may also want to amend further with a mineral additive, such as Gran-I-Grit or even sand, to further increase drainage. Over time, happy gladiolus can naturalize in southern gardens.
Some of my favorite glads are heirlooms with old-fashioned charm (click here for a good source). I also love the elegant Byzantine gladiolus (Gladiolus communis ssp. byzantinus), which is a species bearing long-blooming spires of purple-red summer flowers.
“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 grow Bletilla orchids in my Southern California garden. Do you know of others that don’t need cold? I’m interested in having some more hardy orchids in the ground outside.” Question from Sandra of Thousand Oaks, California
Answer: When thinking of good hardy, terrestrial (ground) orchids for your Southern California garden, seek out area nurseries that offer greenhouse-grown local native orchids or adaptable non-native orchids. You are fortunate to have a fantastic resource in your area, the Santa Barbara Orchid Estate. They recommend several potted and ground orchids for outdoor growing in the Santa Barbara, California and the surrounding area. (Click here to view their outdoor orchid list for beginners.)
They recommend Stenoglottis species and hybrids for in-ground growing where you live. Stenoglottis is an African orchid genus with many types able to withstand your climate. The vigorous, hot-pink hybrid Stenoglottis ‘Venus Jamboree’ is very pretty and comes highly recommended. Give it filtered light and soil with good moisture during the growing season (allow plants to dry between watering during the winter months). You can cultivate them as potted or in-ground plants. Either way, I recommend fortifying their soil with Black Gold Just Coir to increase water-holding potential. (Click here to read about some of my favorite hardy terrestrial orchids. If you can grow Bletilla, you may also be able to grow some of these as well.)
“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:
“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?
Black Gold Horticulturist