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Many gardeners hate weeds. They will curse them under their breath as they drag the roots from the soil and toss them onto the compost pile with relish.
In her well-known book “To Kill a Mockingbird,” Harper Lee describes Miss Maudie’s reaction to a blade of nutgrass with sufficient illustration: “She swooped down upon it with a tin tub and subjected it to blasts from beneath with a poisonous substance she said was so powerful it’d kill us all if we didn’t stand out of the way.”
The silver dollar plant is one of those plants that gardeners tend to see as a weed. And it is indeed an invasive plant species in Virginia, Michigan, and Oregon. While it is lovely, if you live in one of these states, try planting alternatives that add the same interest to your garden.
Now, let’s discuss caring for the silver dollar plant, and how to manage and cultivate one in your garden.
Quick Care Guide
| Common Name(s) | Silver dollar plant, honestly, annual honesty |
| Scientific Name | Lunaria annua |
| Family | Brassicaceae |
| Height and Spread | Up to 3 feet tall and 1 foot wide |
| Light | Full sun to partial shade |
| Soil | Well-draining |
| Water | Keep soil consistently moist |
| Pests and Diseases | Aphids, septoria leaf spot, clubroot, white blister rust |
All About The Silver Dollar Plant
Not all weeds are created the same. Take the Lunaria annua, also known as the money plant, the silver dollar plant, the honesty plant, and moonwort. Because of their rather prolific nature, this plant is sometimes called a perennial.
The very aspects that lead some to consider it a weed can be very useful to a gardener, especially one with children to introduce to the gardening world. They are easy to grow, forgiving if neglected (almost to a fault), and beautiful to behold. And according to lore, having a patch of it may keep your kids honest!
This flowering plant can grow 24 to 36 inches in height. The first year mainly sprouts foliage of heart-shaped leaves but the second year brings fragrant lavender flowers and the famous silvery seed pods that give this plant its names.
If you’re unfamiliar with these fascinating plants, or even if you know them and usually give them wide berth for their weed association, give them a consideration as you read through this guide on silver dollar plant care.
However, note that they are invasive in Virginia, Oregon, and Michigan, and your garden may benefit from removal and replacement with a similar alternative. We’ll discuss how to keep the silver dollar plant in bounds in the Pruning section of this piece.
Planting The Silver Dollar Plant
In all honesty, you could probably just toss a handful of silver dollar plant seeds onto a patch of earth and end up with a lovely group of purple flowers. But if you want to be a bit more deliberate, especially if you have kids learning about gardening, follow these guidelines.
There are several options for timing when it comes to the lunaria plant. Any time after the last frost in the spring or summer is recommended for the first planting. The Lunaria annua is a biennial, meaning you probably won’t see the flowers or seedpods until the next year, so you can stagger their appearance by planting a few seeds in the fall.
Anywhere sunny or lightly shaded will do, though you might want to consider an area that’s easy to tend or contain; the honesty plant doesn’t hold back its self-sowing zeal. This is evidence of its tendency to push out other plants in some gardens.
Silver dollar is hard to transplant, so growing from seed sprinkled on the ground in fall and covered with a light amount of soil is best. Consider spacing 15 to 18 inches apart for good air circulation between grown plants. Allow the seeds to vernalize over winter, and they’ll sprout in spring.
Silver dollar will cozy up to just about any other plant but you might be quite delighted pairing them with various tulips, Forget-Me-Not, and Hakone Grass. If you want to attract more beneficial insects and creatures to your garden, add an herb patch.
Lunaria Annua Care and Cultivation
It’s pretty easy to provide silver dollar plant care. That alone makes it a good choice for children just getting their feet wet in gardening. Honesty plants are quite forgiving!
Light and Temperature
Some gardeners have noted that it doesn’t seem to matter where the seed lands. Lunaria will grow whether it’s sunny or shady, though it may bloom better in sunnier areas. Ideal temperatures for this plant range from 60° to 70° F (16° to 21° C).
As mentioned, seeds need a period of cold stratification is needed for sprouting in spring. It’s hardy in zones 8 to 10, and established plants can withstand frosts and high heat. You plants may need a little shading in hot summers, and some coverage in freezes, however.
Water and Humidity
This money plant prefers to keep its toes moist, so try not to let the soil dry out between waterings. However, do not leave the plant in standing water. In some areas you may need to water only once a week, especially if you have made good use of mulch for continuous moisture.
Soil
This plant will tolerate just about any soil, as long as its well-draining. It likes a bit of fertilizer once or twice a year, but avoid fertilizing in areas where the plant is invasive. In fact, it will appreciate whatever your other plants are getting and may try to take up residence with them over time.
Fertilizer
Again, if you live in a state where Lunaria annua is classed as an invasive species, do not fertilize. This will cause the plant to grow well out of bounds, and push out other plants, many of which are native, threatened, or nearing extinction.
If you have a rich soil, you shouldn’t need to fertilize. Less fertile soils can be treated with a liquid fertilizer diluted to half strength during the growing season.
Harvesting and Storing
One of the most popular parts of this plant is the silvery seed pod, a favorite for dried flower arrangements and imagination games for kids. You can allow the seed pods to dry on the plant or you can snip the stems after the pods turn brown, tie a few together, and hang them to dry.
Harvesting Silver Dollar Seeds
To collect the seeds, wait until they’re brown in the pod. Then rub the pod between your fingers to gently remove the outer layer. If you’d like to use the seed pods in flower arrangements, wait for them to dry out, and snip as needed. Then plop them in your favorite dried arrangement. They’ll last a long time.
Storing
Store the seeds in an air-tight container, someplace dark, cool, and dry. Mason jars, plastic containers, and small envelopes are all appropriate. The seeds should keep for a long time. Cut flowers will remain for a while as well.
Troubleshooting
While this plant is fairly resistant to many pests and diseases, it’s not immune. Here are a few things to watch out for.
Pests
Aphids are little sap-suckers that are usually green but can be red, black, white, or even peach colored. They feed on the underside of the leaf and leave behind “honeydew,” which attracts ants and encourages fungi growth.
A strong blast of water can be enough to shake them off. An application of insecticidal soap may help with larger infestations.
Even better, grow neighboring plants that attract lady beetles to your garden. They think aphids are delicious and will gobble those little buggers into obscurity. A raised bed herb garden with dill and fennel would bring them in nicely.
Diseases
Septoria leaf spot is caused by a fungus and shows up as those little freckle-like holes in leaves, which eventually turn yellow and drop off. Water splashing on the leaves can spread it around. While it doesn’t usually kill, it does weaken the plant and prevent reproduction.
Use a drip irrigation system instead of a sprinkler for watering to cut down on the spread. Use mulch and spacing between plants to allow air to circulate and keep the moisture off the plant. If necessary, use fungicides or rotate new plants to a different area of the garden.
Clubroot looks like yellow, stunted leaves above ground and galls shaped like clubs on the roots below ground. Rotate the plants to a different area and test the soil pH level. If it is acidic, add lime to balance it out.
White Blister Rust distorts plant growth and reduces vigor. Caused by a fungus-like organism, it creates white lesions on leaves that look like white powder when ruptured. Snip and destroy any affected leaves or other debris. Space out the plants for air and reduce splashing of water with mulch and drip irrigation.
Frequently Asked Question
Q: Do Lunaria annua plants attract any good bugs?
A: Yes, they attract butterflies and bees.
Q: Is it deer resistant?
A: Unfortunately not. Unless you’re trying to attract deer, in which case that’s a good thing.
Q: How about container gardening?
A: Containers don’t work too well with this plant: too big, difficult to transplant, and won’t flower until the second year anyway.
Q: Should I save seeds for planting every year?
A: Honestly (there, I did it again!), you probably won’t need to save seeds for planting past the second year. They really do take care of that aspect themselves remarkably well. That being said, you could always save seeds for future garden spots, for friends, for family, and for holiday or birthday gifts. The giving nature is quite strong with this one.
