These compact, rosetted, evergreen perennials, grown as indoor plants, can be tricky and may require some special attention. Heart-shaped leaves (to 2″) are medium green and pubescent. Blooms are delicate and seem quite fragile. Flowers of ‘Delft’ are semi-double, large, blue, with short, prominent, bright yellow stamens. Flowers can reach up to 2″ across. Grows 8″-16″ wide. Needs some bright indirect light to flower, but otherwise needs shelter from light. It is a common misconception that these plants must be watered from below: water on the leaves causes splotches. Not necessarily true. Plants may be watered from above if water is a room temperature. Excessively cold or warm water can be damaging to the plant. If plant is watered from the bottom, do not leave it standing in water for an extended period of time.
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Size: Height: 0.33 ft. to 0.33 ft.
Width: 1 ft. to 1 ft.
Plant Category: houseplants, perennials,
Foliage Characteristics: evergreen,
Flower Characteristics: showy, unusual,
Flower Color: blues,
Bloomtime Range: Early Spring to Late Winter
USDA Hardiness Zone: undefined
AHS Heat Zone: Not defined for this plant
Light Range: Shade to Part Sun
pH Range: 4.5 to 7
Soil Range: Loam to Loam
Water Range: Normal to Moist
FertilizingHow-to : Fertilizing Houseplants
Houseplants may be fertilized with: 1. water-soluble, quick release fertilizers; 2. temperature controlled slow-release fertilizers; 3. or organic fertilizers such as fish emulsion. Water soluble fertilizers are used every two weeks or per label instructions. Controlled, slow-release fertilizers are carefully worked into the soil usually only once during the growing season or per label directions. For organic fertilizers, such as fish emulsion, follow label directions. Allow houseplants to 'rest' during the winter months; stop fertilizing in late October and resume feeding in late February.
LightConditions : Moisture-loving Houseplants
Houseplants that require ample water, or those labeled as moisture-loving houseplants require that they be watered thoroughly until the soil is saturated and then drains freely from holes in the bottom of pot. Re-water when potting soil becomes dry to the touch an inch or so below the soil surface.
Conditions : Bright Light for Houseplants
Houseplants requiring bright light should be placed within 2 feet of an eastern or western exposure window or within 2 to 5 feet of a southern exposure window.
WateringConditions : Normal Watering for Houseplants
Houseplants that require normal watering should be watered so that soil is completely saturated and excess water runs out the bottom of the pot. Never water just a little bit; this allows mineral salts to build up in the soil. The key to normal watering is to allow the top inch or two of potting soil to dry out between waterings. Check frequently as certain times of the year may dictate that you water more frequently. Also, some plants that require normal watering during the growing season, may require less during the winter months when they are dormant.
PlantingHow-to : Potting Indoor Plants
Make sure that the plant you have chosen is suitable for the conditions you are able to provide it: that it will have enough light, space, and a temperature it will like. Remember that the area right next to a window will be colder than the rest of the room.
Indoor plants need to be transplanted into a larger container periodically, or they become pot/root-bound and their growth is retarded. Water the plant well before starting, so the soil will hold the root ball together when you remove it from the pot. If you have trouble getting the plant out of the pot, try running a blade around the edge of the pot, and gently whacking the sides to loosen the soil.
Always use fresh soil when transplanting your indoor plant. Fill around the plant gently with soil, being careful not to pack too tightly -- you want air to be able to get to the roots. After the plant is in the new pot, don't fertilize right away... this will encourage the roots to fill in their new home.
The size pot you choose is important too. Select one that is not more than about 1 inch greater in diameter. Remember, many plants prefer being somewhat pot bound. Always start with a clean pot!
How-to : Repot
Now is the right time to repot.
ProblemsPest : Thrips
Thrips are small, winged insects that attack many types of plants and thrive in hot, dry conditions (like heated houses). They can multiply quickly as a female can lay up to 300 eggs in a life span of 45 days without mating. Most of the damage to plants is caused by the young larvae which feed on tender leaf and flower tissue. This leads to distorted growth, injured flower petals and premature flower drop. Thrips also can transmit many harmful plant viruses.
Prevention and Control: keep weeds down and use screening on windows to keep them out. Remove or discard infested plants, keep them away from non-infested plants. Trap with yellow sticky cards or take advantage of natural enemies such as predatory mites. Sometimes a good steady shower of water will wash them off the plant. Consult your local garden center professional or county Cooperative extension office for legal chemical recommendations.
Pest : Spider Mites
Spider mites are small, 8 legged, spider-like creatures which thrive in hot, dry conditions (like heated houses). Spider mites feed with piercing mouth parts, which cause plants to appear yellow and stippled. Leaf drop and plant death can occur with heavy infestations. Spider mites can multiply quickly, as a female can lay up to 200 eggs in a life span of 30 days. They also produce a web which can cover infested leaves and flowers.
Prevention and Control: Keep weeds down and remove infested plants. Dry air seems to worsen the problem, so make sure plants are regularly watered, especially those preferring high humidity such as tropicals, citrus, or tomatoes. Always check new plants prior to bringing them home from the garden center or nursery. Take advantage of natural enemies such as ladybug larvae. If a miticide is recommended by your local garden center professional or county Cooperative Extension office, read and follow all label directions. Concentrate your efforts on the undersides of the leaves as that is where spider mites generally live.
Pest : Mealybugs
Small, wingless, dull-white, soft-bodied insects that produce a waxy powdery covering. They have piercing/sucking mouth parts that suck the sap out of plant tissue. Mealybugs often look like small pieces of cotton and they tend to congregate where leaves and stems branch. They attack a wide range of plants. The young tend to move around until they find a suitable feeding spot, then they hang out in colonies and feed. Mealybugs can weaken a plant leading to yellow foliage and leaf drop. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.
Prevention and Control: Isolate infested plants from those that are not. Consult your local garden center professional or the Cooperative Extension office in your county for a legal insecticide/chemical recommendation. Encourage natural enemies such as lady beetles in the garden to help reduce population levels of mealy bugs.
Pest : Aphids
Aphids are small, soft-bodied, slow-moving insects that suck fluids from plants. Aphids come in many colors, ranging from green to brown to black, and they may have wings. They attack a wide range of plant species causing stunting, deformed leaves and buds. They can transmit harmful plant viruses with their piercing/sucking mouthparts. Aphids, generally, are merely a nuisance, since it takes many of them to cause serious plant damage. However aphids do produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface growth called sooty mold.
Aphids can increase quickly in numbers and each female can produce up to 250 live nymphs in the course of a month without mating. Aphids often appear when the environment changes - spring & fall. They're often massed at the tips of branches feeding on succulent tissue. Aphids are attracted to the color yellow and will often hitchhike on yellow clothing.
Prevention and Control: Keep weeds to an absolute minimum, especially around desirable plants. On edibles, wash off infected area of plant. Lady bugs and lacewings will feed on aphids in the garden. There are various products - organic and inorganic - that can be used to control aphids. Seek the recommendation of a professional and follow all label procedures to a tee.
Fungi : Powdery Mildew
Powdery Mildew is usually found on plants that do not have enough air circulation or adequate light. Problems are worse where nights are cool and days are warm and humid. The powdery white or gray fungus is usually found on the upper surface of leaves or fruit. Leaves will often turn yellow or brown, curl up, and drop off. New foliage emerges crinkled and distorted. Fruit will be dwarfed and often drops early.
Prevention and Control: Plant resistant varieties and space plants properly so they receive adequate light and air circulation. Always water from below, keeping water off the foliage. This is paramount for roses. Go easy on the nitrogen fertilizer. Apply fungicides according to label directions before problem becomes severe and follow directions exactly, not missing any required treatments. Sanitation is a must - clean up and remove all leaves, flowers, or debris in the fall and destroy.
MiscellaneousGlossary : Evergreen
Evergreen refers to plants that hold onto their leaves or needles for more than one growing season, shedding them over time. Some plants such as live oaks are evergreen, but commonly shed the majority of their older leaves around the end of January.
Glossary : Perennial
Perennial: traditionally a non-woody plant that lives for two or more growing seasons.
Glossary : pH
pH, means the potential of Hydrogen, is the measure of alkalinity or acidity. In horticulture, pH refers to the pH of soil. The scale measures from 0, most acid, to 14, most alkaline. Seven is neutral. Most plants prefer a range between 5.5 and about 6.7, an acid range, but there are plenty of other plants that like soil more alkaline, or above 7. A pH of 7 is where the plant can most easily absorb the most nutrients in the soil. Some plants prefer more or less of certain nutrients, and therefore do better at a certain pH.
Glossary : Flower Characteristics
Flower characteristics can vary greatly and may help you decide on a ""look or feel"" for your garden. If you're looking for fragrance or large, showy flowers, click these boxes and possibilities that fit your cultural conditions will be shown. If you have no preference, leave boxes unchecked to return a greater number of possibilities.