How Do You Get Rid of Canada Thistle?

“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.

  1. 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.
  2. 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.)
  3. 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.)

I hope that these tips help!

Jessie Keith

Black Gold Horticulturist

How Do I Remove Bishop’s Goutweed From My Garden?

“I have, what looks to be Bishop’s vine/weed, growing in my one garden. It’s starting to choke out my tiger lilies and other items growing in the garden. I can’t seem to get rid of it. Is there a way to get rid of the bishop’s weed in my garden?” Question from Angela of Windber, Pennsylvania

ANSWER: Sadly, bishop’s goutweed (Aegopodium podagraria) is a noxious problematic plant when it is unwanted. It can be a notoriously difficult perennial weed to remove. It’s very hardy, and its dense runners spread everywhere quickly, as you have found.  It’s especially annoying when its roots become intertwined with other shrubs and perennials. Here is the four-step approach I recommend that you take to kill it. It may sound challenging, but if you do it right, it is the fastest, most effective way to remove it fast if your garden is not too large. Start the work in the spring as your plants begin to emerge from the soil. (BTY, weed killers are not particularly effective on this plant.)

Four Steps for Goutweed Removal

Goutweed roots will regrow if left in the soil, so remove them all! (image by Drahkrub)
  1. Use a sharp, flat spade, skip the top 4-6 inches of soil to remove as many of the goutweed roots as possible. When digging the underground runners, gently loosen the soil around them with a trowel, following each until they are fully removed. If you keep even a small piece in the ground, it will re-root and grow. This can be a challenge when working around your garden plants, but be diligent. In some cases, you may have to dig up perennials, remove the goutweed roots from their base, and replant them.
  2. To keep underground stems from returning, consider covering the area with mulch cloth and mulching it over. After a season, all goutweed should be smothered, and you can pull up the mulch cloth and resume gardening as usual.
  3. Keep watch for any new goutweed shoots that appear and dig them out immediately.
  4. Look for goutweed that may have crept into your lawn. I recommend using a broad-weed herbicide to remove it. Organic options are available.

I hope that these tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

Can Wild Mushrooms Poison Vegetable Gardens?

“Are wild mushrooms in my vegetable garden a risk if they just disintegrate? Any risk of poisoning the veggies for eating?” Question from Margaret from Chandler, Arizona

Answer: Some wild mushrooms are certainly poisonous, so I recommend removing the fruits from your lawn and garden if you have pets or small children that might consume them. If you have them in your vegetable garden, then your soil may be too moist. Either way, remove the mushrooms as you see them if you have any concerns. It would be wise to wear gloves while handling them. Expert sources say that the spore loads of toxic mushrooms are typically too low to cause any problems. Still, better safe than sorry.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Can I Remove Spider Mites from My Adenium?

“Help!  My 4-year-old Adenium has always thrived.  Last year it put out 6 seed pods and this year the blooms were massive overpowering any green.  When the blooms finally stopped all the older leaves turned yellow and dropped.  But new ones were coming out.  Now the new ones are all curling and while green on the top the bottoms have brown spots.  It’s in the sun all day long and while we had a wet spring (before the blooms) the summer has been dry and hot.  When the leaves started turning yellow (over a month ago) I noticed spider mites so I sprayed them with an insecticide soap for 2 weeks and they are gone but now the leaves are all curled and brown spots on the underside only.  How can I save this plant?” Question from Julie of McKinney Texas

Answer: The good thing is the succulents like Adeniums have lots of stored energy, so once you totally rid them of the spider mites, they will bounce back quickly. To truly eradicate the mites, you will have to spray more than just the foliage.

How to Treat Plants for Spider Mites

Here are the steps I would take to completely remove spider mites from an Adenium.

  1. Remove damaged, yellowing leaves.
  2. Wipe down the base of the plant and stems.
  3. Wipe down the pot.
  4. Remove the top 2 inches of potting mix, and replace it with a quality cactus mix, such as Black Gold Cactus Mix.
  5. Fertilize with a water-soluble fertilizer formulated for flowering plants.
  6. Spray all plant parts with insecticidal soap or Neem oil.

The white-paper test is my favorite way to further test for mites. Take a clean piece of white paper, hold it beneath the leaves, then tap the leaves onto the paper. If you have mites, tiny specs will fall, and eventually, they will start crawling around. These are spider mites. Continue to do the tap test and gently wipe down leaves and stems and spray them until healthy new growth appears and remains undamaged. It may take time, but you can overcome spider mites.

Happy gardening!

Jessie Keith

Black Gold Horticulturist

How Do I Remove Liverwort From My Garden?

“Can I get rid of Liverwort by burying it in the ground?” Question from Russ of Berkley, California

Answer: It depends on the site’s soil, soil level, and moisture level. Admittedly, I kind of like the common liverwort (Marchantia polymorpha). Sorry! But, they’re kind of cool. The funny little non-vascular plants are close relatives of mosses and a sign of a very moist, shaded, nutrient-rich garden area. With that said, I dislike it when they grow in containers, so I understand why you don’t want them in your garden. Here are some different options for liverwort removal.

Change the Soil and Soil Level

The number one way of ridding liverwort from an area is to reduce moisture and fertility, increase soil drainage and aeration, and increase light if you can. (They can’t tolerate dryness or high sunlight.) You can do this by lifting your garden soil in the area where they are causing trouble and adding aggregate to the soil to improve drainage.

Replant With the Right Plants

Another option is to dig up the liverwort, lift the soil, and plant the area with garden plants for your area that will tolerate moisture and shade. Here are a couple of options.

Wood strawberry (Fragaria californica): The California native wood strawberry produces fruit, likes shade to partial shade and grows well in moist soils. It forms an edible groundcover, which might appeal to you.

Idyllwild rock flower (Heuchera hirsutissima): Here is an upland California wildflower that can tolerate moist and dry planting areas as well as partial shade, and it’s very pretty.

Pigsqueak (Bergenia crassifolia): Though it is not native, Bergenia is a pretty evergreen perennial for the shade that produces clusters of pink flowers in late winter and early spring. It likes moist, well-drained soil.

Click here for lots more shade plant options from the California Native Plant Society.

Use Non-Toxic Chemical Methods of Removal

There are approved liverwort controls that contain vinegar, and apparently, they are very effective. (Click here for more information.) I also recommend that you click here to read an excellent overview of liverwort control in greenhouses from Oregon State University. It covers cultural controls as well as chemical ones.

I hope that these liverwort management tips help!

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do I Remove Whiteflies?

“What can I use for whiteflies on Jatropha plants?” Question from Susan of Pembroke Pines, Florida

Answer: I recommend physical methods of removal for whiteflies followed by the use of an insecticide approved for organic gardening.

What are Whiteflies?

Whiteflies are fast-to-produce 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 decline. When plants are badly infested, the undersides of leaves will become covered with clouds of tiny white flies and clusters of their small, round, white egg masses.

How to Remove Whiteflies

Start by spraying the plants off with a sharp spray of water from the hose. Focus on the undersides of leaves. Then look beneath the leaves for clusters of small, white egg masses. Leaves thickly covered with egg massed should be removed, tightly bagged, and thrown away. Next, wipe the small numbers of egg masses off of the remaining leaves. Make sure no eggs remain. Finally, spray the plants with insecticidal soap or Neem 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.

Happy gardening,

Jessie Keith

Black Gold Horticulturist

How Do I Remove Butterfly Bush?

“I just moved into a new house and will be removing a butterfly bush. How much of the root ball do I need to remove so it doesn’t come back?” Question from MaryAnn of Portland, Oregon

Answer: Though beautiful, standard butterfly bush (Buddleia davidii) tend to be very weedy and invasive, which is why gardeners often remove it. Remove the whole root system to make sure that it does not come back. The process will require sharp hand pruners or loppers, good garden gloves, and a sharp, heavy spade. Cut back all of the top growth, so you don’t have branches in the way when you start digging. Then dig deeply around the rootball, and pull it up when it’s fully loose. It should not be too difficult. Butterfly bushes don’t have very dense, deep root systems, so they are fairly easy to remove. Let me know if you want any ideas for replacements!

Happy gardening!

Jessie Keith

Black Gold Horticulturist



How Do I Get Rid of a Groundhog?

“What is the best way to get rid of a groundhog?” Question from Glenn of Parsippany, New Jersey

Answer: Groundhogs can be very destructive creatures as well as smart and evasive. I have dealt with a few around my vegetable garden, and they are real pests! Here are several removal methods that I recommend.

1. Remove cover. Groundhogs dig dens where there is ample green cover. If you can find the den entryways, cut back any cover you can. It will encourage your groundhog to move on. (Some will tell you to pour things down a groundhog’s den hole or smoke them out, but these methods are rarely, if ever, effective. Groundhogs can have as many as 4 to 5 escape exits and can always create a new den.)

2. Live trap: Live trapping them is an iffy venture but worth a try. Offering desirable food within the trap your best bet. Groundhogs are most attracted to tasty, aromatic fruits and vegetables. Contact your local Department of Natural Resources to find out where you can drop off a captured groundhog. (Be sure to wear thick gloves to protect your hands while moving a live-trap cage.)

3. Use motion-activated deterrents: There are motion-activated repelling devices that will scare groundhogs away from your yard or garden when you are not there. These can be quite effective.

4. Get a dog or cat: A dog will do more to scare away a groundhog, but cats can also be helpful, especially large male cats. Groundhogs will clear out if threatened or frightened by a pet.

5. Use copious repellents: If you use some of the methods above in combination with bad-smelling granular or liquid repellents around your yard or garden, you will create a truly undesirable place for groundhogs to reside.

I would also recommend fencing (at least 5-feet high and sunk at least 1-foot below ground), but this can be very expensive. One thing that I do not recommend is the use of poison, which can harm pets, wildlife, and children. Poisons are a real liability and danger.

To get more good ideas, I recommend that you read the article below.

I hope that these tips help!

Happy gardening,

Jessie Keith, Black Gold Horticulturist

Managing the Six Worst Garden Animal Pests

How Do I Kill Trumpet Vine?

“I am having the hardest time killing trumpet vines & they have taken over my yard. I use roundup every year, but it’s not killing the root system.” Question from Rosie of Wichita, Kansas

Answer: Red trumpet vine (Campsis radicans) is a beautiful native vine with giant, trumpet-shaped, orange-red flowers loved by hummingbirds, but as you have discovered,  it is best left for roadside fencelines and natural areas. The vine becomes monstrous and just takes over home landscapes and gardens. Glyphosate, or any other home chemical means, won’t kill it. It requires the toughest measures and a lot of elbow grease to remove.

Trumpet vine is big and woody like a tree, so you have to remove it like a tree. If the vine is still too big, use loppers, and/or pruners to cut it all back. If it’s just popping up everywhere in your lawn, and/or still has a large stump, take a sharp spade and/or mattock and start digging. You’ll have to pull up all the roots, stems, and runners, but it will be a job well worth it. Once you have it all up, you won’t have to deal with it again, hopefully. The occasional sprout may pop up here and there,  in which case dig, don’t spray.

A gentler rambling perennial vine with just as much hummingbird attraction is red honeysuckle (Lonicera sempervirens). It is easily cut back and kept in place. Check out the extra-beautiful variety ‘Major Wheeler’.

Happy gardening!

Jessie Keith

Black Gold Horticulturist


How Do I Keep Ticks off of My Lawn?

“What is the best way of getting rid of ticks? My lawn and yard are infested, and I have gotten Lyme disease.” Question from Kathy of West Rutland, Vermont

Answer: Ticks are the worst and a real worry for people living where Lyme and other tick-borne diseases are a problem. Of course, tiny deer ticks are the carriers of Lyme disease, and they contribute to over 99% of all tick-borne diseases in the state of Vermont, but there are several other larger tick species in the state that can also be problematic.

Six Steps for Tick Removal in Yards and Lawns

Here are six good ways to keep ticks off of your lawn and away from your yard. Some are more practical and doable than others.

1. Spray the yard with all-natural tick repellents and killers, like Tick Killz and Wondercide Flea and Tick Spray. These products can be costly, but they are effective. The best application times are in mid-spring and midsummer.

2. Set tick traps, such as Thermacell Control Tick Tubes,  along your yard’s periphery. These capture and kill ticks and are not a threat to pets or other organisms.

3. Plant tick-repellent plants in your garden and along your yard’s periphery. These include strongly-scented plants such as lavender, sage, mint, feverfew, pennyroyal (this can cause allergic reactions in some people), and marigolds. (Amending your soil at planting time with Black Gold Garden Compost Blend will help all of these plants grow better!)

4. Cut your grass short, bag your clippings, and keep your grass leaf-free. Ticks like to hang out in yard waste and leaves as well as tall grasses and shrubs. Keeping your grass clean and low will help deter ticks.

5. Treat your pets for ticks, and try to keep wild animals out of your yard. Pets and wild animals are tick carriers. Some wild animals, like possums, eat ticks, but most are just carriers. Deer are some of the worst. Applying a quality animal repellant around your yard can help.

6. Consider investing in chickens or guinea hens, which require care and protection but eat ticks in large quantities. You may not have space for chickens, but they will take care of tick populations in the lawn right away, and you’ll get eggs.

I hope that these tips help!

Jessie Keith

Black Gold Horticulturist