Gladiolus ( Obelisk Gladiolus )

These cormous perennials are grown for their showy spiked flowers, which open from the bottom upwards. Foliage is strap-like and vertical. Gladiolus look best when planted in large groups. It is common to stake them. Soil should be fertile and well drained and light may be full sun or partial shade. Hardy in zones 8-10, they may be planted in other areas as annuals or even protected with a thick layer of mulch. For best flowers, fertilize with a high potash fertilizer once spikes reach about 1/2 their height. If glads are not hardy in your area, remove them from the ground roughly 6 weeks after they have finished blooming. Separate the new corms from the old and throw the old ones away. If fungus is a problem in your area, you may want to treat corms with a fungicide prior to separating them.


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Characteristics

Cultivar: Obelisk  
Family: Iridaceae  
Size: Height: 0 ft. to 3 ft.
Width: 0 ft. to 0 ft.  
Plant Category: annuals and biennials, bulbous plants, perennials,  
Plant Characteristics:  
Foliage Characteristics:  
Flower Characteristics: long lasting, showy,  
Flower Color: oranges,  
Tolerances:  


Requirements


Bloomtime Range: Mid Summer to Late Summer  
USDA Hardiness Zone: 8 to 10  
AHS Heat Zone: Not defined for this plant  
Light Range: Part Sun to Full Sun  
pH Range: 5.5 to 7.5  
Soil Range: Sandy Loam to Clay Loam  
Water Range: Normal to Moist  





Plant Care

Fertilizing

How-to : Fertilization for Annuals and Perennials

Annuals and perennials may be fertilized using: 1.water-soluble, quick release fertilizers; 2. temperature controlled slow-release fertilizers; or 3. organic fertilizers such as fish emulsion. Water soluble fertilizers are generally used every two weeks during the growing season or per label instructions. Controlled, slow-release fertilizers are worked into the soil ususally only once during the growing season or per label directions. For organic fertilizers such as fish emulsion, follow label directions as they may vary per product.

Light

Conditions : Full to Partial Sun

Full sunlight is needed for many plants to assume their full potential. Many of these plants will do fine with a little less sunlight, although they may not flower as heavily or their foliage as vibrant. Areas on the southern and western sides of buildings usually are the sunniest. The only exception is when houses or buildings are so close together, shadows are cast from neighboring properties. Full sun usually means 6 or more hours of direct unobstructed sunlight on a sunny day. Partial sun receives less than 6 hours of sun, but more than 3 hours. Plants able to take full sun in some climates may only be able to tolerate part sun in other climates. Know the culture of the plant before you buy and plant it!

Watering

Tools : Watering Aides

No gardener depends 100% on natural rainfall. Even the most water conscious garden appreciates the proper hose, watering can or wand.
    Watering Cans: Whether you choose plastic of galvanized makes no difference, but do look for generous capacity and a design that is balanced when filled with water. A 2 gallon can (which holds 18 lbs. of water) is preferred by most gardeners and is best suited for outdoor use. Indoor cans should be relatively smaller with narrower spouts and roses (the filter head).
    Watering Hose: When purchasing a hose, look for one that is double-walled, as it will resist kinking. Quick coupler links are nice to have on ends of hoses to make altering length fast. To extend the life of your hose, keep it wound around a reel and stored in a shady area. Prior to winter freezes, drain hose.
    Sprayers: Are commonly thought of as devices for applying chemicals, but can really be a step saver for watering houseplants or small pots of annuals rather that dragging out a hose or making numerous trips with a watering can. The backpack sprayer is best suited for this. Take care not to use any kind of chemical in tanks used for watering!
    Sprinklers: Attached to the ends of garden hoses, these act as an economical irrigation system. Standing Spike Sprinklers are usually intended for lawns and deliver water in a circular pattern. Rotating Sprinklers deliver a circle of water and are perfect for lawns, shrubs and flower beds. Pulse-jet sprinklers cover large areas of ground in a pulsating, circular pattern. The head usually sits up on a tall stem, except for when watering lawns. Oscillating sprinklers are best for watering at ground level in a rectangular pattern.


Conditions : Normal Watering for Outdoor Plants

Normal watering means that soil should be kept evenly moist and watered regularly, as conditions require. Most plants like 1 inch of water a week during the growing season, but take care not to over water. The first two years after a plant is installed, regular watering is important for establishment. The first year is critical. It is better to water once a week and water deeply, than to water frequently for a few minutes.

Planting

How-to : Preparing Garden Beds

Use a soil testing kit to determine the acidity or alkalinity of the soil before beginning any garden bed preparation. This will help you determine which plants are best suited for your site. Check soil drainage and correct drainage where standing water remains. Clear weeds and debris from planting areas and continue to remove weeds as soon as they come up.

A week to 10 days before planting, add 2 to 4 inches of aged manure or compost and work into the planting site to improve fertility and increase water retention and drainage. If soil composition is weak, a layer of topsoil should be considered as well. No matter if your soil is sand or clay, it can be improved by adding the same thing: organic matter. The more, the better; work deep into the soil. Prepare beds to an 18 inch deep for perennials. This will seem like a tremendous amount of work now, but will greatly pay off later. Besides, this is not something that is easily done later, once plants have been established.

How-to : Planting Bulbs

Plant bulbs at a depth that is three times their height, and at least 1-1/2 bulb-widths apart. Work a little bone meal fertilizer into the bottom of your hole, and then place the bulb upright in the hole. The more pointed end is almost always the top. If you have trouble telling which is the top, look for evidence of where a stem or roots were last year. If in doubt, plant them sideways. Fill in with soil gently, making sure there are no rocks or clods that would impede the bulb's stem. When planting a great number of bulbs, dig out an area to the specified depth, place bulbs and replace soil. This ensures that ground has been properly prepared and bulbs are evenly spaced.

Plant bulbs in natural drifts rather that formal rows: bulbs can fail or be eaten, leaving holes in a formal arrangement, or will shift with freezing and thawing. If you have trouble with gophers or squirrels eating your bulbs, try sprinkling red pepper in the holes, covering the bulbs with chicken-wire, surround bulbs with sharp shards of gravel or other substance, or planting rodent-repelling bulbs like Fritillaria nearby.

How-to : Planting and Removing Annuals

When planting annuals, begin by preparing the soil. Rototill rotted compost, soil conditioner, pulverized bark, or even builders sand into the existing soil and rake it smooth. Annuals grow quickly, so space them as recommended on plant tags. Remove plants from their containers or packs gently, being sure to keep as much soil as you can around the root ball. If the rootball is tight, loosen it a bit by gently separating white, matted roots with your fingers or a pocket knife. Plant at the same depth they were in the containers. Gently fill in around the plants, providing support but not cutting off air to the roots. Water the plants well.

Through the season, be sure to fertilize for optimal performance. Take special care to cut back or completely remove any diseased plants, as soon as you see there is a problem. At the end of the season, be sure to remove all plants and their root balls. Rake the bed well to prepare it for the next season's planting.

How-to : Planting Perennials

Determine appropriate perennials for your garden by considering sun and shade through the day, exposure, water requirements, climate, soil makeup, seasonal color desired, and position of other garden plants and trees.

The best times to plant are spring and fall, when soil is workable and out of danger of frost. Fall plantings have the advantage that roots can develop and not have to compete with developing top growth as in the spring. Spring is more desirable for perennials that dislike wet conditions or for colder areas, allowing full establishment before first winter. Planting in summer or winter is not advisable for most plants, unless planting a more established sized plant.

To plant container-grown plants: Prepare planting holes with appropriate depth and space between. Water the plant thoroughly and let the excess water drain before carefully removing from the container. Carefully loosen the root ball and place the plant in the hole, working soil around the roots as you fill. If the plant is extremely root bound, separate roots with fingers. A few slits made with a pocket knife are okay, but should be kept to a minimum. Continue filling in soil and water thoroughly, protecting from direct sun until stable.

To plant bare-root plants: Plant as soon as possible after purchase. Prepare suitable planting holes, spread roots and work soil among roots as you fill in. Water well and protect from direct sun until stable.

To plant seedlings: A number of perennials produce self-sown seedlings that can be transplanted. You may also start your own seedling bed for transplanting. Prepare suitable planting holes, spacing appropriately for plant development. Gently lift the seedling and as much surrounding soil as possible with your garden trowel, and replant it immediately, firming soil with fingertips and water well. Shade from direct sun and water regularly until stable.

How-to : Plant Bulbs

It's time to plant bulbs.

Problems

Pest : 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.

Diseases : Bulb Rot

Improperly stored bulbs, or bulbs that are too wet in their dormant stage (usually summer), will be susceptible to fungal diseases that cause them to rot. To prevent this, store bulbs properly when out of the ground. Avoid planting bulbs in poorly drained soils. Fusarium bulb rot can be a serious problem which attacks both the growing plant and stored bulb. Usually introduced by an infected bulb, corm, soil, or even tools, the fungus enters the plant through an abrasion in the tissue. This problem is worse in warm climates where temperatures rarely drop into the freezing range and can persist in soil that stays 60 to 70 degrees Farenheit. Prevention and Control: Buy bulbs that are firm, not mushy. Avoid planting new bulbs in areas where the disease has been present. Unfortunately, there is no treatment for Fusarium bulb rot. Remove all infected bulbs and soil in the immediate area.

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 : Leaf Spots

Leaf spots are caused by fungi or bacteria. Brown or black spots and patches may be either ragged or circular, with a water soaked or yellow-edged appearance. Insects, rain, dirty garden tools, or even people can help its spread.

Prevention and Control: Remove infected leaves when the plant is dry. Leaves that collect around the base of the plant should be raked up and disposed of. Avoid overhead irrigation if possible; water should be directed at soil level. For fungal leaf spots, use a recommended fungicide according to label directions.



Miscellaneous

How-to : Cut Flowers

Flowers suitable for cutting maintain their form for several days when properly conditioned and placed in water or soaked oasis. A cut flower should have a fairly strong, long stem, making it easy to work with in arrangements. There are many short stem flowers that make good cut flowers too, but they look best when floated in a bowl or clustered and placed in a juice glass size vase.

For best results, always cut flowers early in the morning, preferably before dew has had a chance to dry. Always make cuts with a sharp knife or pruners and plunge flowers or foliage into a bucket of water. Store in a cool place until you are ready to work with them, this will keep flowers from opening. Always re-cut stems and change water frequently. Washing vases or containers to rid of existing bacteria helps increase their life, as well.

Glossary : Border Plant

A border plant is one which looks especially nice when used next to other plants in a border. Borders are different from hedges in that they are not clipped. Borders are loose and billowy, often dotted with deciduous flowering shrubs. For best effect, mass smaller plants in groups of 3, 5, 7, or 9. Larger plants may stand alone, or if room permits, group several layers of plants for a dramatic impact. Borders are nice because they define property lines and can screen out bad views and offer seasonal color. Many gardeners use the border to add year round color and interest to the garden.

Glossary : Low Maintenance

Low maintenance does not mean no maintenance. It does mean that once a plant is established, very little needs to be done in the way of water, fertilizing, pruning, or treatment in order for the plant to remain healthy and attractive. A well-designed garden, which takes your lifestyle into consideration, can greatly reduce maintenance.

Glossary : Mass Planting

Mass is one of the elements of design and relates directly to balance. Mass planting is defined as the grouping of three or more of the same type of plants in one area. When massing plants, keep in mind what visual effect they will have. Small properties require smaller masses where larger properties can handle larger masses or sweeps of plants.

Glossary : Sandy Loam

Sandy Loam refers to a soil that drains well, with excellent air space, and evenly crumbled texture when squeezed in the hand. A good workable garden soil that benefits from added fertilizer and proper watering. Dark gray to gray-brown in color.

Glossary : Loam

Loam is the ideal soil, having the perfect balance between particle size, air space, organic matter and water holding capacity. It forms a nice ball when squeezed in the palm of the hand, but crumbles easily when lightly tapped with a finger. Rich color ranges between gray brown to almost black.

Glossary : Clayey Loam

Clayey loam refers to a soil that retains moisture well, without having a drainage problem. Fertility is high and texture good. Easily forms a ball when squeezed in the hand, and then crumbles easily with a quick tap of the finger. Considered an ideal soil. Usually a rich brown color.

Glossary : Annual

An annual is any plant that completes its life cycle in one growing season.

Glossary : Bulbs

A bulb is a modified, underground stem.

Glossary : Perennial

Perennial: traditionally a non-woody plant that lives for two or more growing seasons.

Glossary : Long Lasting

Long Lasting: having blossoms that last for an extended period of time. Some plants may have the appearance of providing long lasting flowers because they are prolific, repeat bloomers.

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 : Heat Zone

The 12 zones of the AHS Heat Zone map indicate the average number of days each year that a given region experiences ""heat days"" or temperatures over 86 degrees F(30 degrees Celsius). That is the point at which plants begin suffering physiological damage from heat. The zones range from Zone 1 (less than one heat day) to Zone 12 (more than 210 heat days). The AHS Heat Zone, which deals with heat tolerance, should not be confused with the USDA Hardiness Zone system which deals with cold tolerance. For example: Seattle, Washington has a USDA Hardiness Zone of 8, the same as Charleston, South Carolina; however Seattle's Heat Zone is 2 where Charleston's Heat Zone is 11. What this says is that winter temperature in the two cities may be similar, but because Charleston has significantly warmer weather for a longer period of time, plant selection based on heat tolerance is a factor to consider.

Glossary : Plant Characteristics

Plant characteristics define the plant, enabling a search that finds specific types of plants such as bulbs, trees, shrubs, grass, perennials, etc.

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.

Glossary : Foliage Characteristics

By searching foliage characteristics, you will have the opportunity to look for foliage with distinguishable features such as variegated leaves, aromatic foliage, or unusual texture, color or shape. This field will be most helpful to you if you are looking for accent plants. If you have no preference, leave this field blank to return a larger selection of plants.

Glossary : Soil Types

A soil type is defined by granule size, drainage, and amount of organic material in the soil. The three main soil types are sand, loam and clay. Sand has the largest particle size, no organic matter, little to no fertility, and drains rapidly. Clay, at the opposite end of the spectrum, has the smallest particle size, can be rich in organic matter, fertility and moisture, but is often unworkable because particles are held together too tightly, resulting in poor drainage when wet, or is brick-like when dry. The optimum soil type is loam, which is the happy median between sand and clay: It is high in organic matter, nutrient-rich, and has the perfect water holding capacity.

You will often hear loam referred to as a sandy loam (having more sand, yet still plenty of organic matter) or a clay loam (heavier on the clay, yet workable with good drainage.) The addition of organic matter to either sand or clay will result in a loamy soil. Still not sure if your soil is a sand, clay, or loam? Try this simple test. Squeeze a handfull of slightly moist, not wet, soil in your hand. If it forms a tight ball and does not fall apart when gently tapped with a finger, your soil is more than likely clay. If soil does not form a ball or crumbles before it is tapped, it is sand to very sandy loam. If soil forms a ball, then crumbles readily when lightly tapped, it's a loam. Several quick, light taps could mean a clay loam.

How-to : Getting the Most Out of Cut Flowers

Cut flowers bring the garden into your home. While some cut flowers have a long vase life, most are highly perishable. How cut flowers are treated when you first bring them home can significantly increase how long they last.

The most important thing to consider is getting sufficient water taken up into the cut stem. Insufficient water can result in wilting and short-lived flowers. Bent neck of roses, where the flower head droops, is the result of poor water uptake. To maximize water uptake, first re-cut the stems at an angle so that the vascular system (the ""plumbing"" of the stem) is clear. Next immerse the cut stems in warm water.

Remember when the flower is cut, it is cut off from its food supply. Once water is taken care of, food is the resource that will run out next. The plants stems naturally feed the flowers with sugars. If you add a bit of sugar (1 tsp.) to the vase water, this will help feed the flower stems and extend their vase life.

Bacteria will build up in vase water and eventually clog up the stem so the flower cannot take up water. To prevent this, change the vase water frequently and make a new cut in the stems every few days.

Floral preservatives, available from florists, contain sugars, acids and bacteriacides that can extend cut flower life. These come in small packets and are generally available where cut flowers are sold. If used properly, these can extend the vase life of some cut flowers 2 to 3 times when compared with just plain water in the vase.

How-to : Selecting and Storing Bulbs

Larger bulbs will generally produce larger, healthier plants. Bulbs that are small for their species type will have small or no flowers the first year, but may pick up in their second year. Daffodils with two points will have two flower stalks if both bulb parts are large enough.

Select bulbs that have intact skins or ""tunics"". These plants are less vulnerable to disease. When buying bulbs with split tunics, look for areas that appear diseased on the flesh of the bulb. It's much like shopping for onions. Some smaller bulbs, like Lily of the Valley ( Convallaria) or Snowdrops ( Galanthus), will establish better if you can buy them when they're in leaf, instead of dry bulbs.

You should plant your bulbs as soon as you can. You have purchased them in a dormant period, and you want them in the ground when they come out of it. If you can't plant your bulbs right away, store them in a dark, cool, dry place. Gasses given off by fruit can cause bulbs to rot; keep this in mind if storing your bulbs in a refrigerator. Some bulbs are better stored in slightly damp peat moss or shavings; if your bulb was stored this way when you bought it, continue to store it this way.



Glossary : Viruses

Viruses, which are smaller than bacteria, are not living and do not replicate on their own. They must rely on the cellular mechanisms of their hosts to replicate. Because this greatly disrupts the cell's functionality, outward signs of a viral infection result in a plant disease with symptoms such as abnormal or stunted growth, damaged fruit, discolorations or spots.

Prevention and Control: Keep virus carriers such as aphids, leafhoppers, and thrips under control. These plant feeding insects spread viruses. Viruses can also be introduced by infected pollen or through plant openings (as when pruning). Begin by keeping the pathogen out of your garden. New plants should be checked, as well as tools and existing plants. Use only certified seed that is deemed disease-free. Plant only resistant varieties and create a discouraging environment by rotating crops, not planting closely related plants in the same area every year.

Glossary : Fertilize

Fertilize just before new growth begins with a complete fertilizer.

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