Plant Care American Knotweed

American Knotweed

Also known as

Narrow-leaf knotweed, Northern knotweed, Birdweed, Common knotgrass, Pigweed, Prostrate knotweed and Lowgrass

Taxonomy

Polygonum aviculare
Polygonum
Polygonaceae
Caryophyllales

How to care for American Knotweed

💦 Water

How often to water your American Knotweed

Water needs for American Knotweed
0.5 cups
every 9

American Knotweed needs 0.5 cups of water every 9 when it doesn’t get direct sunlight and is potted in a 5" pot.

Use our water calculator to personalize watering recommendations to your environment or download Greg for more advanced recommendations for all of your plants.

Calculate water needs of American Knotweed

Water 0.5 cups every
9

Does your plant get direct sunlight?

Select the pot size

5"
☀️ Light

Finding light for American Knotweed in your home

Light needs and placement for plant American Knotweed: 1ft from a window
1ft or less from
a window

American Knotweed love being close to bright, sunny windows 😎.

Place it less than 1ft from a south-facing window to maximize the potential for growth.

American Knotweed does not tolerate low-light 🚫.

Select your region to see how the current weather in your area affects the placement of American Knotweed in your home 🏡.

🪴 Nutrients

How to fertilize American Knotweed

Nutrient, fertilizer, and repotting needs for American Knotweed: repot after 2X growth

Most potting soils come with ample nutrients which plants use to produce new growth.

By the time your plant has depleted the nutrients in its soil it’s likely grown enough to need a larger pot anyway.

To replenish this plant's nutrients, repot your American Knotweed after it doubles in size or once a year—whichever comes first.

💡 FAQs
💦 Water Needs

American Knotweed prefers for the soil to dry out between waterings and should be watered regularly. Use our water calculator to personalize watering recommendations to your environment or download Greg for more advanced recommendations for all of your plants.

American Knotweed Water Frequency →

American Knotweed Root Rot →


☀️ Sunlight Needs

American Knotweed requires abundant, bright and direct light. Place it less than one foot from a window to ensure it receives enough light to survive 💪. Select your region to see how the current weather in your area affects the placement in your home 🏡.

American Knotweed Light Requirements →

American Knotweed Direct Sunlight Needs & Tolerance →


🐶 🐈 👶 Toxicity

Greg does not have confirmed data on this plant’s toxicity. If you, a family member, or a pet consumes plant material of unknown toxicity, it’s always best to consult a medical professional.

If you or someone else ingested this plant, call Poison Control at US (800) 222-1222. If a pet consumed this plant, contact your veterinarian or the ASPCA at US (888) 426-4435.


🪴 Soil

American Knotweed is very sensitive to dry soil, so choose a potting soil that retains moisture. A good soil will still drain well and contain lots of organic matter such as coco coir or sphagnum moss.

When and How to Successfully Repot American Knotweed →


💩 Fertilizer

American Knotweed grows very slowly and doesn’t require added fertilizer. Replacing your plant’s potting soil once a year should provide them with more than enough nutrition. Remember, plants get their energy from sunlight, not fertilizer!

How Much and When to Fertilize American Knotweed →


⬆️ ⬇️ Growth Pattern

American Knotweed grows along the ground and sends out shoots which will spread across the soil.

How and When to Prune American Knotweed →


🌦️ Growing Outdoors

USDA Hardiness Zone
American Knotweed can be grown outdoors in USDA Hardiness Zones 2a-10b. Find your local hardiness zone here.

American Knotweed Temperature Tolerance →


🌱 Propagation

The seeds of American Knotweed can be used to grow new plants! After your plant flowers, any seeds that formed can be collected and germinated in potting soil.


🧐 Troubleshooting

When troubleshooting a sad-looking houseplant, start by checking for signs of distress in its leaves, such as yellowing, browning, or drooping, which can indicate overwatering or nutrient deficiencies.

Inspect the soil moisture; too dry or too wet soil can cause problems.

Ensure the plant is getting the right amount of light, as too much or too little can stress it.

Finally, consider environmental factors like temperature and humidity, and adjust care routines accordingly to revive your plant.


Care Summary for American Knotweed

American Knotweed

American Knotweed


Greg recommends:

Water

0.5 cups every 9 days

Placement

< 1ft from a window

Nutrients

Repot after 2x growth

Based on the 4” pot your plant is in, and that it doesn’t get direct sunlight.

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