New Guinea impatiens (Impatiens hawkeri) provide a spectacle of blooms in any sunny garden location. Like their cousins the common impatiens, which likes to grow in shade, the New Guinea impatiens grow in small groups of leaves with lots of colorful flowers. These plants will bloom early in the season if planted right after the last chance of frost. Some varieties will even bloom well into fall. New Guinea impatiens are a high-performing, low-maintenance choice for gardeners who want a showy seasonal display with little work.
This type of impatiens has pointy leaves that are dark green, burgundy, and speckled. They look nice all season long. The flowers come in shades of orange, pink, red, white, and purple, and the blooms look like but are bigger than common impatiens. The flowers of New Guinea impatiens consist of five heart-shaped petals. The flowers of this plant are perfect for a pollinator garden because they attract butterflies and other good bugs.
With their bright, abundant blooms and easy care nature, new guinea impatiens are a favorite for gardens across many regions. Getting these beautiful plants established and keeping them thriving over the season relies heavily on providing the right temperature conditions
New guinea impatiens prefer warm weather and consistent temperatures within an ideal range. Too hot or too cold, and these otherwise carefree flowers may struggle, wilt, or fail to bloom their best.
By understanding the optimal temperature window for new guinea impatiens and how to keep them in their comfort zone, you can enjoy a stellar display of color in your garden beds, containers, or borders.
What’s the Ideal Temperature Range for New Guinea Impatiens?
New guinea impatiens thrive best with daytime high temperatures between 70-85°F (21-29°C). Nighttime lows should remain above 55°F (13°C), ideally in the 55-65°F (13-18°C) range.
These tender tropical plants originate from the warmer, humid regions of New Guinea and adjacent Indonesia. They need warm soil and air temperatures to establish, grow, and flower their best.
Temperatures cooler than 60°F (16°C) can cause new guinea impatiens to sulk. Growth may slow and the abundant blooms may be reduced or absent altogether.
On the opposite end, excessively hot temperatures above 85°F (29°C) can also create stress. The plants may wilt or scorch and have difficulty flowering steadily in extreme heat.
Key Temperature Thresholds
Here are some key temperature thresholds to understand when growing new guinea impatiens:
- Minimum temperature: 55°F (13°C)
- Optimal daytime range: 70-85°F (21-29°C)
- Optimal nighttime range: 55-65°F (13-18°C)
- Maximum tolerable temperature: 90°F (32°C)
Aim to keep your new guinea impatiens within these ideal parameters for optimal growth and maximum flower production through the season.
How to Keep New Guinea Impatiens in Their Comfort Zone
With some planning and attentive care, you can maintain the preferred temperature range for your new guinea impatiens over the growing season Here are some tips
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Wait for warming soil & air – Plant new guinea impatiens outdoors only after day and night temperatures have warmed above 60°F (16°C) consistently.
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Provide afternoon shade – Give plants relief from intense midday sun to prevent overheating.
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Use wind barriers – Block excessive wind which can cool the plants.
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Monitor with a thermometer – Check temperatures around the plants daily to catch any extremes.
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Water early in the day – Avoid wet foliage at night which can chill plants.
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Use row covers or cloches – Drape fabric over plants at night if cooler temperatures are predicted. Remove during the day.
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Move containers indoors or under cover – Bring potted new guinea impatiens into a garage, patio, or indoors overnight if needed to protect from cold.
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Mulch beds – Spread 2-3 inches of bark chips, compost, or other organic mulch around plants to insulate soil.
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Provide supplemental heating – Use cloches, cold frames, or other season extension devices to add warmth when temperatures drop.
With some adjustments throughout the seasons, you can easily keep your new guinea impatiens happy in their ideal temperature niche.
What Happens if Temperatures Are Too Low?
New guinea impatiens are considered cold intolerant. Chilling damage can occur once temperatures drop below 60°F (16°C). Here’s what you may observe if the plants get too cold:
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Slowed growth – Cool temperatures inhibit rapid growth. Plants remain small and sparse.
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Lack of blooms – Flower buds fail to form or blooms drop off altogether in cold conditions.
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Leaf damage – Leaves may turn greasy-looking or develop dark water-soaked spots due to chilling injury.
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Wilting – Entire plants may droop or collapse in very cold weather.
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Rot diseases – Excess moisture alongside cool air promotes fungal issues like botrytis, downy mildew, or root rot.
If new guinea impatiens fail to thrive, check that nighttime temperatures are not falling outside their preferred range. Protect them or provide warmth as needed.
What About High Temperatures?
While new guinea impatiens appreciate and require warmth, excessive heat can also create issues. Here’s what may occur if temperatures climb too high:
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Wilting or drooping – Leaves and flowers wilt in an effort to conserve moisture when overly hot.
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Poor flowering – Extreme heat causes flower buds to blast or drop. Blooms decrease.
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Leaf scorch – Leaf edges or tips turn brown or crispy from heat and dryness.
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Sunburn damage – Direct sun plus heat can scorch leaves, causing bleached spots.
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Slowed growth – High heat stresses the plants, resulting in stunted size and lackluster appearance.
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Pest problems – Aphids, spider mites, and other pests thrive and reproduce in hot, dry conditions.
Take action to prevent overheating if your new guinea impatiens start showing these signs of heat distress.
Adjusting Care Through the Seasons
Managing temperatures for new guinea impatiens requires some seasonal adjustments:
Spring
- Hold off planting until soil & air warm above 60°F (16°C) overnight.
- Watch weather forecasts for any late cold snaps or frost threats.
- Provide row covers at night if cooler temperatures are predicted after planting.
Summer
- Give afternoon shade, especially on hotdays over 85°F (29°C).
- Mist plants on very hot days or move to shadier spots.
- Ensure adequate moisture to prevent wilting.
Fall
- Begin moving containers to sheltered areas as nights cool.
- Use season extending devices like cold frames or cloches.
- Stop fertilizing 6 weeks before expected first frost.
Winter
- Bring containers indoors before frost arrives.
- Take cuttings to propagate plants for next year.
- Discard garden plants after first hard freeze.
Adjusting your practices to account for seasonal shifts in temperatures will keep your new guinea impatiens flowering happily.
Pairing Temperature Control With Proper Humidity
Along with ideal temperatures, new guinea impatiens also appreciate moderately humid conditions. Their native tropical climate is marked by high rainfall and humidity.
While new guinea impatiens don’t necessarily require very high humidity to thrive, a complete lack of moisture in the air can lead to stressed, underperforming plants.
Aim to grow new guinea impatiens in average home humidity levels. Supplement moisture with regular misting or use pebble trays if the air is very dry.
Proper watering techniques that focus on moistening the soil rather than wetting foliage will also help maintain favorable humidity around your plants.
Achieving Success With New Guinea Impatiens
Paying close attention to temperature factors is one of the keys to success with new guinea impatiens. Taking some simple steps to control their environment allows these otherwise easy-going plants to flourish.
A little extra care to shield your new guinea impatiens from temperature extremes can make all the difference in your garden display. Maintain vigilance through the seasons to keep them blooming reliably within their ideal comfort zone.
With the right amount of warmth from spring through fall, your new guinea impatiens will reward you with vivid color and abundant flowers. Just focus on providing the proper temperature range, and enjoy the vibrant show.
Water
New Guinea impatiens thrive with regular waterings. Not letting them stay dry for a long time will cause them to stop blooming and maybe even die. New Guinea impatiens can’t handle drought, but their crowns may rot if the soil stays wet for a long time. Avoid watering them from the top, and use a drip hose instead, if possible.
Pruning
New Guinea impatiens require some mid-summer pruning in order to maximize the blooms. To do so, first, deadhead the flowers by pinching the stem back to its first set of leaves. You can do this regularly throughout the season. Next, look for areas where the stems have grown leggy and are producing more foliage than blooms. Remove no more than 6 inches of stems from the middle of your impatiens if they become spindly.
You don’t need to prune your impatiens if their flowers look full and have no holes in them.
Everything You Need to Know About New Guinea Impatiens | Plant Encyclopedia | Better Homes & Gardens
FAQ
What is the lowest temperature New Guinea impatiens can tolerate?
How cold can impatiens tolerate?
Can New Guinea impatiens tolerate morning sun?
What are the best conditions for New Guinea impatiens?
How much sun do New Guinea Impatiens need?
The amount of sun exposure your New Guinea impatiens need depends on the temperature and moisture of your climate. New Guinea impatiens do best with morning sun and afternoon shade in a garden with eastern exposure. If the sun is bright and the temperatures extreme, impatiens will require more water and may not bloom as profusely.
How do you care for New Guinea Impatiens?
Avoid watering them from the top, and use a drip hose instead, if possible. Do not plant New Guinea impatiens outside until all danger of frost has passed and night temperatures are above 45 F. These flowers prefer day temperatures of 70 to 85 F and night temperatures of 55 to 65 F. They thrive in the high-humidity zones of 10, 11, and 12.
When should I plant New Guinea Impatiens?
Since New Guinea impatiens don’t respond well to cool nighttime temperatures (below 45℉), it’s best to plant them about 2 weeks after the last spring frost. The sweet spot for growing them is when daytime temperatures hover between 70 and 85℉ and nighttime temperatures fall between 55 and 65℉.
Are New Guinea Impatiens drought tolerant?
New Guinea impatiens thrive with regular waterings. Do not let them remain dry for an extended period of time or they will stop blooming and potentially die. New Guinea impatiens are not drought tolerant, yet prolonged periods of wet soil may cause their crowns to rot. Avoid watering them from the top, and use a drip hose instead, if possible.
