How Often to Water Outdoor Potted Plants

Watering outdoor potted plants can seem like a balancing act – providing enough moisture for healthy growth, but not so much that roots rot from overwatering. The frequency of watering depends on many factors, including the plant variety, pot size and drainage, weather and exposure. With careful observation and adjusting as needed, you can maintain a good watering routine for your patio, porch or deck containers.

Getting to Know Your Plants’ Needs

When determining how often to water, start by understanding your plants’ preferences. Certain varieties naturally prefer more or less frequent watering.

Plants That Enjoy Frequent Watering

• Annual flowers – Petunias, marigolds, zinnias and geraniums often thrive with frequent watering. Check these plants daily in hot weather.
• Vegetable plants – Tomato, pepper and cucumber plants in containers need consistent moisture, checked daily during summer heat.
• Tropical houseplants – Transplanted outside for the summer, tropicals like orchids, palms and hibiscus want frequent watering.

Plants That Prefer Infrequent Watering

• Succulents – Cacti, aloe and other succulents store water in their leaves. Allow soil to dry between waterings.
• Mediterranean Herbs – Rosemary, lavender, thyme and oregano prefer their soil to dry out some between waterings.
• Native Plants – Hardy, drought-resistant natives like prairie grass and coneflowers thrive with less frequent watering.

If combining plants with different needs in one container, aim to water for the plant that needs the most moisture. Or consider choosing plants with similar watering preferences.

Pot Size Matters

The size of the container greatly impacts watering frequency. A small volume of soil dries out faster than a larger amount.

• Small pots under 10 inches wide may need watering daily in summer.
• Larger containers over 12 inches wide can go 2-3 days between waterings.
• Extra large planters may only need water every 4-7 days if the plants are not thirsty varieties.

To extend time between waterings, choose large containers whenever possible. For small pots, self-watering inserts can reservoir moisture.

Soil Drainage Affects Frequency

Soil that retains too much moisture leads to overwatering. Ensure containers have adequate drainage holes and use a well-draining soil blend.

• For indoor potting mix, amend with added perlite or pumice for better drainage.
• Cactus mixes work well for succulents and xeriscape plants.
• Fast draining commercial blends like Miracle-Gro Cactus, Palm & Citrus mix promote healthy roots.

Improving drainage means less frequent watering is needed. But if soil drains too fast, plants may dry out sooner. Find the right balance.

Weather Conditions Guide Schedules

Outdoor plants need more frequent watering in hot, dry weather than cool, damp conditions. Adjust as seasons change.

Hot, Dry Weather

• Temperatures over 85°F – Plants transpire (release moisture) faster and soil dries quickly. Check pots daily.
• Windy conditions – Accelerates moisture loss. May need to water twice a day.
• Full sun exposure – Causes faster transpiration. Water morning and evening.
• Rainless weather – Without rain, rely only on watering. Don’t let pots completely dry out.

Cool, Damp Weather

• Temperatures under 75°F – Slower transpiration means slower soil drying. Water every 2-4 days.
• Calm, windless days – Less moisture lost through leaves. Check pots every 3 days.
• Partial shade – Further reduces transpiration needs. Water when soil just begins to feel dry.
• Frequent rain – Supplements your watering. Let soil partly dry between rains.

Observing Your Plants

Plants show visible signs when they need water. Observe them closely each day.

Signs Plants Need Water

• Wilting or drooping leaves that perk up after watering.
• Soil pull-away from the pot edge.
• Soil surface is dry to the touch. Depth depends on plant.
• Leaves changing color or drying at tips and edges.
• Slowed growth and small new leaves.
• Daily water needs vary by season, weather and other factors.

Clues Plants are Overwatered

• Wet soil that takes a full day or longer to partly dry.
• Mushy stems and leaves.
• Yellowing leaves that drop or wilt.
• White fungal growth on soil surface.
• Roots rotting – turn brown/mushy.

If a plant shows overwatering signs, allow soil to dry further before next watering. Remove mushy parts.

How to Tell if Outdoor Potted Plants Need Water

It takes a trained eye to read plants’ signals and determine when to water. Here are common techniques:

The Finger Test

This is the most direct way to assess soil moisture. Use your finger to check soil:

• Push finger 1-2 inches into soil and feel for moisture. Depth depends on the plant.
• Soil should feel cool and slightly damp but not soggy wet.
• If soil is dry, it’s time to water thoroughly.

Realize that the surface can feel dry even when deeper soil still has moisture. Check different depths.

Lift or Tap the Pot

Gently lift or tap the pot to gauge its weight:

• Heavy pot – Soil still retains enough moisture. No need to water yet.
• Light pot – Soil is drying out and likely ready for watering.
• Very light pot – Soil is too dry. Water immediately.

This takes practice but soon you’ll recognize dried out pots.

Visually Inspect Plants

Closely study leaves and stems for signals like:

• Wilting or dull looking leaves – Needs water.
• Perky leaves – Probably has enough moisture.
• Slowed growth – Time to water.

Combine visual signs with the finger or lift test to decide whether to water.

Use a Moisture Meter

These specialized tools measure moisture levels in soil:

• Probe is inserted in soil for a reading of “wet vs. dry”.
• Helps take the guesswork out of judging moisture.
• Easy to use but can be expensive for casual use.

If struggling to get watering right, a meter takes the mystery out of knowing when to water.

Watering Methods and Volume

How you deliver water to plants also affects frequency. Give plants a deep soaking at each watering.

Hand Watering with Hose or Watering Can

• Water slowly and deeply until excess drains from holes.
• Don’t stop until soil is thoroughly saturated.
• Takes more time but is most thorough.

Wait until soil is partly dry before next watering. Time varies by season and plant size.

Drip Irrigation Systems

• Drip lines or soaker hoses apply slow moisture at soil level.
• Can water automatically on timer.
• Keeps foliage dry to prevent disease.

Adjust timer seasonally to provide adequate water without over-saturating soil.

Self-Watering Planters and Reservoirs

• Built-in water reservoirs hydrate plants between fillings.
• Release moisture as soil dries out.
• Check reservoir every 2-4 days in summer.

Refill reservoir before it runs dry. Change out old water occasionally.

Volume Depends on Pot Size

• Small pots – May take only cups per watering.
• Medium pots – Require 1-2 gallons per watering.
• Large containers – Can need 5+ gallons of water when soil is dry.

Apply enough water to moisten entire root zone but not leave soil soggy.

Tips for Proper Outdoor Potted Plant Watering

Avoid common mistakes that lead to watering problems. Consistency and vigilance are key.

• Check soil moisture every day in hot weather.
• Water thoroughly until excess drains from holes.
• Adjust schedule for weather changes, plant needs and growth rate.
• Allow soil to partly dry between waterings.
• Observe plants daily for under or overwatering signs.
• Water in the morning so leaves dry by night.
• Feel soil at different depths to check for moisture.
• Ensure containers have drainage holes to prevent soggy soil.

Adopt best practices and know your plants’ preferences for healthy container gardens.

Frequently Asked Questions About Watering Outdoor Potted Plants

Watering outdoor container plants properly is vital yet can be confusing. Here are answers to some common FAQs.

How much water do outdoor potted plants need?

The amount varies based on factors like weather, plant size, soil volume and drainage. As a general rule, give plants enough water so it drains freely from the pot’s bottom. For a medium 8-10 inch pot, this is often 1-2 gallons.

How often should I water container plants outside?

During hot summer weather, most pots need watering at least every 2-3 days, or even daily for small containers or thirsty plants. In cooler or wet weather, you may only need to water every 4-7 days. Check soil and observe plants daily.

Is it better to water outdoor pots in the morning or at night?

Watering early in the day allows plant leaves and soil to dry by evening, preventing disease. Avoid nighttime watering. But if plants wilt severely in the afternoon, give them a drink of water to recover.

Should I let outdoor container plants dry out completely between waterings?

No, allowing pots to completely dry out stresses plants. But don’t keep soil constantly wet either. Let soil partially dry out between waterings, about 1-3 inches deep depending on the plant.

What causes outdoor potted plants to die?

The primary reasons container plants die are overwatering, underwatering and extremes of weather. Insufficient drainage leading to wet soil and root rot is a very common problem. Use well-draining soil and pot with holes.

How do I know if my outdoor potted plants need more water?

Plants signal their needs if you know what to look for. Signs they need more water include drooping leaves, wilting, leaves changing color, soil pulling away from the pot edge and feeling dry to the touch.

Should I use mulch in outdoor potted plant soil?

Mulching container plants is not generally needed and takes up valuable room in pots. The exception is using a thin layer of small pebbles or gravel to help reduce evaporation in very small containers.

Is rain enough for outdoor potted plants?

Outdoor plants appreciate a drink of natural rainwater. But rain alone may not sufficiently water plants in times of drought or heat waves. Also, pots under roof overhangs miss rain. Supplement with manual watering as needed.

Can I overwater plants in outdoor pots?

Yes, it’s easy to overwater container plants! Allow the soil to partially dry out between waterings to prevent waterlogged conditions. Signs of overwatering include soggy soil, yellowing leaves and mushrooms on the soil surface.

Conclusion

The art of proper watering takes time to master but following a few key guidelines makes it easier. Choose container plants suited to your climate. Know their moisture preferences. Check soil frequently, observing plants for their needs. Water thoroughly, adjust for weather, and avoid extremes of too wet or too dry. With practice, you can maintain healthy and thriving potted plants outdoors.