Plants are the lens Jessie views the world through because they’re all-sustaining. (“They feed, clothe, house and heal us. They produce the air we breathe and even make us smell pretty.”) She’s a garden writer and photographer with degrees in both horticulture and plant biology from Purdue and Michigan State Universities. Her degrees were bolstered by internships at Longwood Gardens and the American Horticultural Society. She has since worked for many horticultural institutions and companies and now manages communications for Sun Gro Horticulture, the parent company of Black Gold. Her joy is sharing all things green and lovely with her two daughters.
“What’s the best way to ensure that my blue [bigleaf] hydrangea stays blue?” Question from Gaye of Saint Peters, Missouri
Answer: It all has to do with soil pH. There are two hydrangeas that have flowers whose color changes depending on whether the soil is acidic (3.5-6.8), alkaline (7.2-10), or neutral ( around 7). These are bigleaf hydrangeas (Hydrangea macrophylla, Zones 5-11) and Japanese mountain hydrangeas (Hydrangea serrata, Zones 6-9). If your flowers are on the pinker side then your soil is more alkaline, and if they are erring towards purple then your soil is more neutral. To achieve flowers with a bluer hue, you will need to lower your soil pH. There are several ways to do this.
“How can I tell when an underground veggie (onion, potato, etc) is ready to harvest. I have tried growing onions and I get large green growth above ground and there is basically a marble-sized onion bulb underneath — or smaller!” Question from Naomi of Oakdale, California
Answer: It’s an excellent question. In most cases, it is pretty easy to tell because most root crops bulb up at the top. You can expect this to happen with beets, onions (see image below), radishes, turnips, and rutabagas. It also happens to carrots and parsnips, though sometimes their bulbous tops are less prominent.
Potatoes, sweet potatoes, and garlic are different matters. These tuberous (or bulbous in the case of garlic) crops remain underground, so you need to gauge how the plants up top are growing to determine harvest time. Here are guidelines for harvesting each.
Potatoes: “New Potatoes can be harvested as soon as the plants begin to bloom. Wait for larger potatoes. These can be harvested after the plants have fully died away. You can harvest all of your potatoes at this time for storage, or just harvest them as needed. Be sure to get them all out of the ground shortly after the first frost of the season. Otherwise, they will develop an unpleasant sweet flavor.” (Click here to read the full Ask a Garden Expert.)
Sweet Potatoes: “Sweet potatoes are harvested 90-120 days after transplanting or immediately after a frost has blackened the tops of the plants.” (Click here to read the full article.)
“I would like to fertilize some small blueberry plants I bought this year. I have your BLACK GOLD RHODODENDRON, AZALEA & EVERGREEN FERTILIZER, and I have some questions about its use because I don’t understand the instructions. It says “new plantings, 500ml per 1.5 m squared. Or 1.5 cups for every inch of diameter of the trunk. My plants are nowhere near 1-inch in diameter. I have a round pot, 15 inches diameter, and I have another plant, in a 14 X 20” rectangle. Also, doesn’t the depth matter as well when determining how much fertilizer to put in? Here are three more questions.
How do I know how much fertilizer to put in?
It says “measure 6 inches above the soil line”. What is the soil line? Then you say “the drip line”. What is the drip line?
The instructions say to mix the fertilizer in with the soil. How do you do that once the plant is already potted?”
Question from JM of Toronto, Canada
Answer: We are happy to answer your question about how to apply Black Gold Rhododendron, Azalea & Evergreen Fertilizer. Here are the answers to your three primary questions.
You will need to extrapolate from the guide suggestion: “Add 1.5 cups for every inch of diameter of the trunk.” For example, if the stem of your blueberry is approximately 1/2 inch in diameter, then work in 3/4 cup (175 mL) of fertilizer around the root zone of your blueberry. If it is smaller, extrapolate to add less.
The soil line is the soil layer that covers the roots, while the drip line is the diameter area of the plant crown. Please see the schematic below.
If you are adding fertilizer to a pot, then gently work it into the soil around the roots from the top. You do not need to work it in deeply. The fertilizer will make its way down to feed your plants every time you water.
“What is the best for growing the juiciest plumpest fruits and veggies?” Dave from Springfield, Massachusetts
Answer: Give your fruits and vegetables the best care possible and make sure that you water and fertilize regularly. (Click here for a full vegetable garden growing guide.) It sounds obvious, but limiting environmental and physical stresses as well as those from pests and diseases will also ensure good production and well-developed fruits and vegetables. Uninhibited plants invest their energy into good growth and fruit development rather than self-protection. Happy plants produce happy fruits. Also, be sure to choose fertilizers that encourage flower and fruit development. (Click here for a full article about vegetable garden fertilization from Colorado State University.)
Variety selection is also an important consideration. Some vegetable and fruit varieties are plumper and juicier than others, so make sure that you choose those that are described as being large, juicy, and flavorful. For example, go for big beefsteak tomatoes rather than standard tomatoes, and choose extra blocky pepper varieties rather than thinner-walled types. (Click here to learn more about growing prize beefsteak tomatoes.)
One more tip: Refrain from overwatering when fruits are nearly ripe. Excess water late in the fruiting stage can cause fruit splitting and water down the flavor. This is especially the case with tomatoes and melons.
Many native honeysuckles are adapted for hummingbird pollination.
I love the honeysuckles (Lonicera japonica) of old. Their fragrance is unmatched, and their nectar-filled flowers sweet to taste. But sadly, the rampant, rambling wild vines are Asian in origin and unfriendly to North American landscapes. They take over; smothering native landscapes in a sweetly-scented blanket of blooms. There is, however, an upside. There are loads of native, non-invasive honeysuckle vines, loved by hummingbirds, bees, and butterflies, that stay put and look great in gardens.
Hummingbird-Pollinated Honeysuckles
A number of native North American honeysuckle vines are unusual in that they are adapted to pollination by hummingbirds rather than bees and butterflies. Hummingbirds see red and orange, have little to no sense of smell, and need lots of tubular flowers filled with energy-rich nectar to dip their bills into. That’s why these honeysuckles have tubular flowers loaded with sweet nectar, come in shades of red and orange, and generally lack scent. The twining, wood vines are very colorful and long-blooming, so they offer a great display of color in addition to attracting lots of hummingbirds to the garden. All grow and flower best in full sun and appreciate average to fertile, well-drained soil. Here are some of the best to grow.
Trumpet Honeysuckle
Red trumpet honeysuckle is a sure performer that hummingbirds will visit!
Trumpet honeysuckle (Lonicera sempervirens, USDA Hardiness Zones 4-8, 12-20 feet) is a native vine that bears clusters of orange, red, or gold trumpets in summer. It can be found across the eastern United States in meadows and open woodlands. It has been heavily bred for cultivation. Some of the best varieties include ‘Major Wheeler’, a profuse, summer-long bloomer with large clusters of orange-red trumpets. The yellow-flowered ‘John Clayton‘ is such an impressive bloomer, it can flower from early summer to frost. The extra-large, yellow-throated, red trumpets of ‘Blanche Sandman‘ are very colorful and maintain the same manner of bloom–nonstop through summer–as do the large, coral-red blooms of ‘Honey Coral‘.
Brown’s Hybrid Honeysuckle
The flared orange flowers of ‘Dropmore Scarlet’ are lovely and prolific.
Brown’s hybrid honeysuckle (Lonicera x brownii (L. sempervirens and L. hirsuta), Zones 4-9, 10-20 feet) is a vigorous flowering vine with flared tubular blooms. The best-known variety is the prolific ‘Dropmore Scarlet‘ with its orange (not scarlet) tubular blooms, blue-green foliage, and appealing red berries that follow the flowers and are eaten by songbirds.
Arizona Honeysuckle
The Southwest-Native Arizona honeysuckle (Lonicera arizonica, Zones 5-6, 4-6 feet) is a short-vined hummingbird-pollinated honeysuckle that has all of the bells and whistles of the other two above with one added benefit–excellent heat and drought tolerance. There are few flowering vines that will grow as well as this one in the hot, dry American southwest. Still, it will grow and flower best with some additional irrigation, so plan to water on occasion. Amend its soil with Black Gold Garden Compost Blend at planting time, and plant it in a location where it gets some midday or afternoon shade.
Bee- and Butterfly-Pollinated Honeysuckles
American honeysuckles that feed native long-tongued bees and butterflies tend to be fragrant and colorful. There are quite a few spectacular types offered at garden centers. Here are several of the best.
Heckrott’s Honeysuckle
Gold Flame Honeysuckle (Lonicera x heckrottii ‘Gold Flame) is an award-winning cross between a native and non-native honeysuckle.
These are highly fragrant honeysuckles! The famed Gold Flame Honeysuckle (Lonicera x heckrottii ‘Gold Flame) is an award-winning hybrid that received the Royal Horticultural Society‘s Award of Merit. The exceptional vine is a cross between one European (Lonicera x americana (Lonicera implexa x Lonicera etrusca)) and one American (Lonicera sempervirens) species. The vines are long-blooming, fragrant, and the clusters of tubular flowers come in spectacular shades of pink, gold, magenta, and red. According to the USDA Plants Database, this partially native hybrid has not shown itself to be invasive in American landscapes.
Yellow Honeysuckle
A native of East-Central United States, yellow honeysuckle (Lonicera flava, Zones 5-8, 10-20 feet) is a pretty flowering vine that bears lots of golden yellow or orange flowers in summer. The flowers have a lightly sweet fragrance and are visited by bees, butterflies, and the occasional hummingbird. They are followed by orange-red berries that are eaten by birds.
Grape Honeysuckle
Grape honeysuckles are unusual native vines with cups that surround the yellow flowers and grape-like fruits.
The unusual looks of Kintsley’s Ghost Grape Honeysuckle (Lonicera reticulata Kintzley’s Ghost®, Zones 4-8, 8-12 feet) deserve more attention from gardeners. The East-Central US native has vines decorated with leaves that encircle the stem and cup-like bracts that support clusters of yellow flowers that feed native bees. Kintzley’s Ghost® is even more spectacular because the foliage is eucalyptus-blue, which really sets off the bright flowers.
Siting Honeysuckles
This sturdy, wrought-iron arbor supports a red trumpet honeysuckle.
Most of these rambling vines need a sunny, sturdy arbor, fence, pergola, or trellis to grow upon. Plant them in soil that is average to fertile and drains well. Prune and thin the vines yearly to keep them from becoming too overgrown and to disable a build-up of dying stems beneath. Regular pruning and shaping will also encourage good flowering. Honeysuckles typically bloom on new growth.
“What is the best organic way to get rid of whiteflies?” Question from Shawn of Kenosha, Wisconsin
Answer: Whiteflies can become awful pests to manage if the populations become large, but they are relatively easy to kill. Here is a little more information about these pests and some organic methods for handing them.
What Are Whiteflies?
Whiteflies are sucking insects that remove the juices from plant leaves and stems. Tiny whiteflies can be very destructive when populations are high–causing leaf drop and general plant decline. When plants are badly infested, the undersides of leaves will become covered with clouds of tiny flies that are bright white and clusters of their small, round, white egg masses.
Whiteflies breed continuously and quickly, which is a big reason why they are so problematic. According to Colorado State University: At 70º F, the greenhouse whitefly life cycle happens fast. “It takes 6-10 days for egg hatch, 3-4 days as a nymph I, 4-5 days as nymph II, 4-5 days as nymph III, 6-10 days for the pupa. Adults can live for 30 to 40 days.” Adults produce lots of eggs for ever-increasing numbers unless challenged.
How to Kill Whiteflies
Start by spraying the plants off with a sharp spray of water from a hose. Focus on the undersides of leaves. Then look beneath the leaves for clusters of clinging, small, white egg masses. Leaves thickly covered with egg masses should be removed, tightly bagged, and thrown away. Next, wipe the egg masses off of the remaining leaves. Make sure no eggs remain. Finally, spray the plants with insecticidal soap, Neem oil, or horticultural oil. (Click here for an overview of horticultural oils for organic insect control.) Continue to check for whiteflies and wipe and spray leaves as needed.
It may take a little work, but this method is effective.
“Hi — I just transplanted tomato starts from the bathtub to larger containers and used Black Gold All Purpose for much of it. I had one bag of All Purpose and one of Natural, Organic. I noticed that the All Purpose has more fertilizer in it. The Natural Organic has less, but it is natural and organic. Still, I’m thinking I should generally use the All Purpose — because it seems like the transplanted tomatoes have really benefited from the fertilizer in it (more than they might benefit from what’s in the Natural/Organic). What’s your perspective? I don’t think it’s my imagination that the tomato starts to look quite a bit better after transplanting into the All Purpose. I’m just not sure if they’ll do roughly equally well in the Natural and Organic Potting Soil. There’s less fertilizer. I don’t see the differences clearly yet with my starts for reasons that I won’t bore you with. Please advise. :-)” Question from Steve of Bow, Washington
Answer: The Black Gold All Purpose Potting Mix contains supplemental fertilizer to feed plants for up to six months, while Black Gold Natural & Organic Potting Soil contains no added fertilizer. That’s why you saw better growth in the seedlings planted in the All Purpose, but both are good choices for potted vegetable growing. I would also add that tomatoes are very heavy feeders, so I recommend adding fertilizer that is specially formulated for tomatoes anyway. There are loads of fertilizer options for tomatoes on the market.
We have several other soils that are ideal for tomato growing because they hold extra water and are OMRI Listed for organic gardening. These are Black Gold® Natural & Organic Flower and Vegetable Soil, which is very porous and fertile, and Black Gold Natural & Organic Ultra Coir, which holds extra water for thirsty tomatoes. From there, I recommend that you watch the video below with great tips for how to successfully grow tomatoes in containers.
“I live in the San Fernando Valley – Woodland Hills alongside the 101 freeway which follows the Los Angeles River. The soil is horrible – topsoil atop the riverbed, which was diverted to a cement-based flow. How do I build it up – besides gypsum – are there plants more suited to help break it up long term.” Lorraine of West Hills, California
Answer: Your soil sounds very hardpan and tough. Upon research, I found this quote: “Soil in Woodland Hills tends to be hard, compact clay…the curse of most Valley gardeners” -Melinkoff, 1987. Thankfully, there are measures that you can take to add fertility to your soil and loosen it up a bit for easier gardening.
The trouble with clayey soils is that they lack aeration, good drainage, and become very hard when dry. This disables water percolation and the fine roots of plants from gathering necessary air and moisture for top performance. Here are several measures that I would take to improve soil performance.
Add Organic Matter
For organic amendments to be effective in clay soils, they need to be evenly incorporated in quantity. Add amendments, like compost, peat moss, earthworm castings, and composted manure, into your soil at a ratio of two parts amendment to one part ground soil. Till them in or work them in with a turning fork when your clay soil is damp. Make sure they are well incorporated. The deeper you amend, the more you will improve bed performance. You might also consider berming your soils to lift them above the soil level. (Click here to learn more about berming.) Organic amendments should be added yearly to maintain good fertility.
Adding mineral components, like gypsum, can also increase the porosity and improve the structure of clay soils. A hefty application of gypsum will certainly help improve soils heavy in clay. Other minerals, like granite dust, greensand, and lime, may also be helpful in this manner. Mineral components should be applied along with organic matter for a better long-term solution to loosening and improving clay soils.
Add Topsoil
True topsoil generally contains a generous amount of loamy mineral soil with better porosity and fertility than yours because loams contain even parts sand, silt, and clay. Mix it into your beds at a 1:1 ratio, being sure to incorporate the two soils well. If you incorporate topsoil into your beds, as well as regular organic matter, you will be set!
Choose Raised Beds
Finally, you can build your beds upwards. Raised beds are an excellent choice for gardeners living in areas with poor soils. I recommend that you watch the video below that details raised bed pros and cons.
“How does one get rid of [Canada] thistle?” Question from J Marsh of Fenton, Michigan
Answer: I am so sorry that you have this plant in your garden. Canada thistle (Cirsium arvense) is by far one of the worst of all garden weeds. It has painfully prickly foliage and produces lots of early summer flowers that produce copious puffy seeds that are distributed by wind and seed in everywhere. Once established, one plant can create a dense colony connected by rooting rhizomes that are impossible to dig out because they root several feet down. If you leave just one root piece, it might form a whole new plant. Canada thistle is also resistant to herbicides. Here are three ways to remove it.
Dig and Smother Canada Thistle
One of the best all-natural methods is smothering plants with weed cloth and mulch until they are gone. This one will also creep into the grass, so try to keep lawn specimens under control with broadleaf herbicide. You also don’t want to let this one go to seed anywhere near your yard or garden. Here are the steps that I recommend.
Methodically dig out the underground runners. Gently loosen the soil around each with a trowel, following them until the growing points are reached and the roots are fully removed. If you keep even a small piece in the ground, it will regrow.
If the runners are intertwined with perennial roots, dig up the perennials, and remove the thistle roots in full. (Before replanting, amend the soil with Fafard Premium Natural & Organic Compost for faster re-establishment.)
To keep underground roots from returning in really infested areas, cover the area with mulch cloth and mulch it over. After a season, all parts should be smothered, and you can pull up the mulch cloth and resume gardening as usual.
Scorch Canada Thistle
Canada thistle wedged between pavers or sidewalks can be repeatedly torched with a weed blow torch or flamethrower. It is a useful method for difficult-to-reach weeds. Solarization is another method of heat-based eradication. Summer is the best time to solarize bed areas. To do it, mow or trim back weeds in the area and then simply cover the weedy space with an impermeable layer of thick clear plastic. Use landscape pins to hold it down. Keep it in place for eight weeks or more, until the weeds below have died. In theory, this method will kill plants to the root. (Click here for more details.)
Get a Professional to Use Professional-Grade Herbicides on Canada Thistle
I am generally not a proponent of heavy-duty herbicide use, but some weeds require it. If you choose this avenue, then I recommend having a professional do the work. The herbicides needed to kill thistle are quite toxic and not nice to handle. (Click here for a great info sheet for garden professionals.)
“Is there a type of ornamental tree that I can plant within 6 feet of my house (in zone 5)?” Amy of Grand Rapids, Michigan
Answer: Aside from being attractive and suited to your garden and area, any tree that you choose must be compact and have a root system that is somewhat shallow. Here are five selections that are both beautiful, compact, and native.
Lavender Twist® Weeping Redbud (Cercis canadensis ‘Covey’): This small tree reaches between 8-12 feet when fully mature, but its weeping crown maintains a tidy, compact appearance. Redbuds are native to eastern North America and have beautiful spring flowers of purplish-red. Grow this one in full sun and well-drained fertile soil.
Spring Glory®Serviceberry(Amelanchiercanadensis ‘Sprizam’): White spring blooms, edible summer fruits that attract birds, and orange-red fall leaves make this an outstanding 12-foot small tree for home gardens. Grow this one in full to partial sun.
Golden Shadows®Pagoda Dogwood (Cornus alternifolia ‘Wstackman’): The gold and green foliage of this 10- to 12-foot variegated dogwood will light up any partially shaded location around the home.
Fringe Tree (Chionanthus virginicus): Loads of delicate, fringed, fragrant ivory flowers in spring make this small tree an excellent specimen to plant near a home. Mature specimens may reach 12 to 20 feet, so this is on the larger end of what you can plant close to the home. Full to partial sun is preferred.
Blue Arrow Juniper(Juniperus scopulorum ‘Blue Arrow’): Here’s an evergreen option that hails from Colorado. It has tidy blue-green foliage and a narrow, upright habit. Trees reach just 12 feet at maturity. Full sun is required.
