Water

Attribute	Value
Agastache ‘Bolero’	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Alam Potschke New England Aster	Like many other flowers, New England asters like moist soil. They can tolerate lower levels of soil moisture as long as it’s not completely dry to the touch. Water your plants well during stretches with no rainfall.
Annabelle Hydrangea	If you live in a region with hot, dry summers or your shrub is growing in the north in full sun, you'll need to provide your smooth hydrangea with supplemental irrigation during the growing season. It needs moist conditions, and a layer of mulch to help retain moisture.
Apache Sunset Hummingbird Mint	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Astilbe	The warmer the weather, the more moisture astilbe plants need, especially when situated in full sun. They do not handle prolonged periods of drought well; the leaves will brown and dry, and if left dry too long, the plants will die. In the absence of rain, water astilbe weekly and deeply at the base, avoiding overhead watering. Keep the soil moist but not soggy.
Autumn Joy Stonecrop	Autumn Joy does not need much water and has excellent tolerance for drought. Even in the heat of summer, light watering every two weeks or so is sufficient. More frequent watering can cause the roots to rot.
Balmy Beebop Bee Balm	Unlike other bee balm species, spotted bee balm does not need watering except when newly planted until it’s established, and during periods of extended drought when its leaves are wilted or start dropping. Otherwise, spotted bee balm is fairly drought-tolerant.
Balloon Flower ‘Sentimental Blue’	Keep the soil of young plants consistently moist but not soggy. Once established, balloon flowers like a moderate amount of moisture in the soil, but they can tolerate short periods of drought. They won’t need a lot of supplemental watering unless you have a long period without rainfall that causes the soil to dry out.
Balloon Flower ‘Astra White’	Keep the soil of young plants consistently moist but not soggy. Once established, balloon flowers like a moderate amount of moisture in the soil, but they can tolerate short periods of drought. They won’t need a lot of supplemental watering unless you have a long period without rainfall that causes the soil to dry out.
Black Adder Anise Hyssop	Water newly planted Anise Hyssop weekly, if there is no rainfall, for the first four weeks. Water slowly and deeply, welcoming deep, spreading roots. Once plants are established, cease watering. Being drought tolerant, they are very easy to grow and care for.
Black Tupelo	The tree likes moist soil and should be watered regularly when it is young to maintain even soil moisture. However, it also has some drought tolerance, and mature trees can adapt to growing in relatively dry soils. Still, if you have a prolonged period without rainfall and your soil begins to dry out, you should water your tree.
Blackberry Lily	While blackberry lilies respond to regular watering by producing larger, healthier blooms, they are also drought tolerant. Dry winter soils are ideal. Err on the side of less water, not more. If your garden is getting rain every week or two, extra irrigation is rarely necessary. During drought periods, 1/2 inch per week is entirely adequate. Water should be cut back during the dormant winter months to discourage root rot.
Bleeding Heart	Bleeding heart likes a lightly moist soil. It doesn't tolerate soggy or dry soils very well. Water throughout the growing season when the top inch of soil has dried out, even during summer dormancy to keep the roots hydrated. But make sure the soil doesn't stay waterlogged, which can lead to root rot.
Bloody cranesbill	Geraniums are a low-maintenance plant, so water them only when the soil gets dry. If located in full sun, water the plant more frequently. Hardy geraniums can become prone to fungal disease if watered overhead.
Blue Blazes Hummingbird Mint	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Blue Jean Baby Russian Sage	New transplants need regular watering, but once established, Russian sage is very drought-tolerant. It likes medium to dry soil and will do fine in hot, dry areas of your yard or garden. Russian sage will not grow well in excessively wet, poorly-draining soil.
Blue Indigo	Keep a false indigo watered regularly for the first year, but after this, it will do well with about 1 inch of water every couple of weeks. Once established, Baptisia is relatively drought-tolerant. This is a native wildflower, and in most regions, it does fine with whatever rainfall nature provides.
Blue Mouse Ears Hosta	Water hostas as needed to keep the soil moist but not wet. Once established, hostas will tolerate occasionally dry soil, but they won't survive long periods of drought. Deeper, infrequent watering is better than frequent shallow applications. When growing hostas in pots indoors, maintain a regular watering schedule to keep the soil moist.
Carpet Phlox	This plant requires a moderate amount of soil moisture, though mature plants do have some drought tolerance. Unless you have rainfall, it will generally need watering weekly, especially during the heat of the summer.
Catmint Walker's Low	First-year plants need frequent watering, every couple of days during the first week, then about one inch of water per week for at least one more month in the absence of rain. Once established, catmints are drought-tolerant and don't need watering.
Coral Bells	This plant has medium water needs and likes consistently moist soil. Established plants will tolerate some drought, but an inch of water per week is the best way to keep them happy. If you grow your coral bells in full sun, plan to give them extra water—their shallow roots will need extra moisture during hot, sunny days.
Cranberry Lace Bee Balm	A regular watering schedule is best for these plants, especially during the first year of growth. Bee balms need evenly moist soil and won’t do well with overwatering or neglect. Water these plants once the soil just begins to feel dry. To prevent problems with powdery mildew, water at ground level and avoid getting the foliage wet.
Creeping Phlox	This plant requires a moderate amount of soil moisture, though mature plants do have some drought tolerance. Unless you have rainfall, it will generally need watering weekly, especially during the heat of the summer.
Cushion Spurge	Water the perennials well after planting. After that, it is no longer necessary to water the plant additionally. You should only give the cushion spurge water during long periods of dry and hot periods – but only a little.
Fireball Bee Balm	A regular watering schedule is best for these plants, especially during the first year of growth. Bee balms need evenly moist soil and won’t do well with overwatering or neglect. Water these plants once the soil just begins to feel dry. To prevent problems with powdery mildew, water at ground level and avoid getting the foliage wet.
Fringed Loosestrife	Your variegated lysimachia plant should be watered regularly to ensure the soil does not dry out. If you notice the leaves losing their vibrancy or browning around the edges, that's a good indication that the plant is not receiving enough water. Generally, about 1 inch of water (from rainfall or manual watering) per week will be sufficient, though you may need to increase your watering cadence if you're experiencing particularly hot or dry weather.
Goldenrod	Water new goldenrod plants weekly to maintain damp, but not soggy soil. Mature goldenrod plants are drought tolerant and rarely need supplemental watering except when rainfall is scarce.
Great Blue Lobelia (aka Blue Cardinal Flower)	Keep the soil evenly moist, but not soggy. In areas with regular rainfall, you might not need to provide extra water. In drier areas, however, be prepared to water your lobelia every few days through the summer, and more often if the weather is exceptionally hot.
Hardy Hibiscus	If you can't locate hardy hibiscus plants in a moist spot in your landscape, make sure to keep the plants adequately watered—but don't overdo it. A hardy hibiscus is typically thirsty and needs a deep watering of at least 1 to 2 inches of water per week and needs to be watered almost everyday. A small plant with fewer leaves needs less water than a large, leafy plant. A good indicator that your plant needs watering is when an inch down into the soil is dry.
Little Lanterns Dwarf Columbine	Columbine requires moderate soil moisture, so apply water when the top inch or two of soil dries out. As young plants are becoming established, keep the soil evenly moist but never soggy. Established plants only need watering about once a week. Mulch the plants to conserve water in the summer.
Love-in-a-Mist	Love-in-a-mist likes consistent moisture, Water it slowly but deeply until the top couple of inches of the soil are well-saturated.
Karen Azalea	Azaleas need water to bloom, and spring rain showers usually do the job. However, if the spring is dry, extra watering can be beneficial.
Kudos Coral Hummingbird Mint	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Kudos Gold Agastache	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Kudos Mandarin Agastache	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
My Castle Lupine	While lupines don't like soggy soil, which can cause root rot, they prefer regular waterings. Water at least weekly if you haven't gotten rainfall to prevent the soil from drying out.
Oakleaf Hydrangea	These plants appreciate moist soil, and the more sunlight they receive, the more water they need. Blanketing the ground beneath the shrub with a thick layer of mulch will help maintain soil moisture.
Orange Daylily	Water young plants at least weekly to keep the soil moist but never soggy. After the first year, you likely won’t have to water your mature daylilies unless your area is going through a prolonged drought. But note that the plants prefer roughly an inch of water per week and will produce more blooms if they have optimal moisture.
Penstemon 'Blackbeard'	Penstemons tolerate drought, but 1 inch of water per week in the summer will keep plants vigorous and promote better blooming.
Red Maple	Red maples prefer somewhat moist soil but will grow fine in dry soils provided you are willing to irrigate them regularly (slow, deep watering is the ideal). Once established, make sure the soil remains moist—a layer of organic mulch around the base of the tree will help. Make sure the tree gets a deep watering each week, either by irrigation or by rainfall; do not let the soil dry out.
Rose Campion	This plant likes a moderate amount of water, but it can tolerate dry soil. Water young plants regularly as their root system becomes established. A good rule of thumb is to water whenever the top 2 inches of soil have dried out. Make sure the soil is never waterlogged, as this can cause root rot.
Rose of Sharon	Rose of Sharon grows best in moist soil, but mature shrubs can tolerate some drought. It won't thrive extremes: very dry or very wet conditions. So, don't let the soil fully dry out, and make sure your shrub isn't sitting in waterlogged soil.
Russian Sage	New transplants need regular watering, but once established, Russian sage is very drought-tolerant. It likes medium to dry soil and will do fine in hot, dry areas of your yard or garden. Russian sage will not grow well in excessively wet, poorly-draining soil.
Siberian Iris	Because the Siberian iris is susceptible to crown rot, do not intentionally saturate its soil. Light, regular watering is preferable. During spring and the first part of summer, make sure it receives about one inch of water per week through rainfall or irrigation. Later in the summer, it can get by with an every-other-week watering schedule.
Snow Crocus	Crocuses are generally low-maintenance plants. They like to be watered regularly in the spring and fall. If there is no snow cover, the bulbs will also need water throughout the winter. However, they go dormant in the summer and prefer drier soil during this time.
Stiff Goldenrod	Water new goldenrod plants weekly to maintain damp, but not soggy soil. Mature goldenrod plants are drought tolerant and rarely need supplemental watering except when rainfall is scarce.
Swamp Milkweed	Keep this plant moist. If given a proper wetland environment, the swamp milkweed will likely not need watering throughout the growing season.
Sweet woodruff	While sweet woodruff grows most vigorously in damp to wet soil conditions, it also tolerates dry shade. To prevent it from spreading too invasively, only water the plant in times of prolonged drought.
Tango Hummingbird Mint	Though it enjoys a deep watering, consistently moist conditions are not suitable for agastache. Watering routines should ideally follow desert conditions: occasional blasts of heavy rain followed by days of hot sun.
Tiger Lily	Tiger lilies have average water needs. Mature plants can tolerate some drought, but they still prefer consistent watering. If your area receives regular rainfall, that should be sufficient to keep them happy. If the soil is very dry, you'll probably need to water on a regular basis to prevent the soil from drying out.
Witch's Moneybags	Autumn Joy does not need much water and has excellent tolerance for drought. Even in the heat of summer, light watering every two weeks or so is sufficient. More frequent watering can cause the roots to rot.
Yellow Evening Primrose	Evening primrose does best with adequate regular watering and will need a bit more water if grown in an especially hot climate during the summer. However, if you notice any discoloration or browning on the plant's many leaves, that's a sure sign that your evening primrose is getting too much water and is likely suffering from root rot or a fungal disease.