A Summer-Long Punch of Color: Growing Annuals in the Garden

A bed of mixed annuals including tender perennials, summer bulbs, seed grown flowers and colorful grasses.

A bed of mixed annuals including tender perennials, summer bulbs, seed grown flowers and colorful grasses.

Annuals have certainly come a long way since the humble red geraniums and simple zinnias of the past.  These days, nurseries are overflowing with mounds of colorful and exotic flowers of every size and shape.

So whether you’re looking to create a lavish window box, add a little curb appeal to your front walk, or  just fill in a few gaps between your shrubs and perennials, an infusion of annuals may be just what your garden needs to get it from now to wow!

Technically, “annuals” are plants which complete their life cycles (grow, flower, set seed, and die) within one year or growing season. They include flowers, vegetables, herbs, ground covers, and vines. Plants labeled “tender perennials” are best treated as annuals in our hardiness zone, as they will likely not survive our winters and, therefore, will not return the next year as true perennials will.

Window boxes are great for showcasing annuals. Make sure they have holes for drainage and are big enough to accommodate your plants as they grow. Because window boxes dry out quickly, they will need frequent watering. To keep soil and water from spilling out when watering, don’t fill boxes all the way up to the top with soil. Instead, leave at least half an inch of space between the soil line and the rim of the container. This allows water to puddle and slowly soak in, which not only keeps siding from being splashed with mud, but also provides plants with deeper, more effective watering.

Designing Annual Flowerbeds

Sectioning large annual beds into grids can ensure adequate spacing between plants and make it easier for designs drawn on paper come to life.

Annual flowerbeds can be created by laying garden hose or twine on the ground until the appropriate shape is obtained. Use this marker as the pattern to edge out the bed.  Bed lines can be straight or rounded, but curved lines are always more visually interesting.

Planning the design on paper with the correct spacing for a given plant will help assure that you have the right number of plants for your design. Keep taller annuals to the back of the border, and dwarfs and low annuals to the front.

In established beds, sectioning off planting grids can aid in plant placement, making sure that overall spacing is even and each variety has enough room to grow.

The sky’s the limit when it comes to color selection. There are so many vibrant primary and soft pastel colors available that endless combinations are possible.  Don’t only consider flower color when it comes to annuals. Lots of annuals offer interesting foliage or interesting seed heads, even veggies can add a fun, unexpected element.

When it comes to annuals, don’t limit your thinking to flowers alone, vegetables –like these ornamental peppers– make great additions to gardens and containers.

How to Plant Annuals

SITE SELECTION: Different plants have different requirements for sun, shade, soil quality, and drainage. Most annuals prefer full sun, rich garden soil, and good drainage.

One of the best things about annuals is their incredible diversity in color, form and texture– providing exciting combinations that last all summer.

Other factors to consider when choosing where to plant your annuals are visibility, (i.e. will you be able to see and enjoy them where they are planted?) and accessibility for maintenance (will you be able to get to them to remove dead flowers, to weed, and to fertilize?)  The average flower border should be no wider than 5 to 6 feet, so the middle can be accessed from both sides without stepping into the garden.

SOIL PREPARATION: Most annuals need soil that is loose enough for the roots to grow easily. Adding organic matter to heavy (clay) soil will help loosen it. Organic matter also can be added to sandy soil. For the average garden bed, add 1 inch of compost, peat moss, or well-rotted manure to the garden.

Have a soil test run to determine the pH or relative acidity. If lime is needed to raise the pH of an acid soil, apply according to soil test recommendations or use 3 to 5 lbs. of lime for each 100 sq. ft.

FERTILIZER: Annuals grow quickly and need fertilizer to nourish that growth. Use a complete fertilizer, either chemical or organic, such as 10-10-10, 5-10-10, or 5-10-5 applied at the rate of 2 lbs. per 100 sq. ft. and rake or spade into the soil before planting. Side dress at mid-season as required by individual plants. Plants may be sprayed with liquid seaweed, fish emulsion, manure or compost tea several times during the season.

PLANTING – SEED: Follow seed packet instructions for distance apart and correct depth of planting. Timing of planting is also important, because some seeds are not frost or cold tolerant and must be sown when the soil is warm. Cover the seeds with fine soil and water thoroughly.

If you raise your own plants from seed make sure they are “hardened off” for a week before transplanting. Tender plants usually sunburn or die if not hardened off by stopping fertilizer applications, lowering temperature, and increased ventilation. Gradually expose them to outdoor conditions before the transplant date.

Select short, stocky plants with dark green foliage. Avoid tall, spindly plants. Small to medium-sized transplants become established in the garden more quickly than large ones.

PLANTING – TRANSPLANTS: Select healthy, robust seedlings in individual pots or 6-8 packs from your garden center. Reject any plants that appear stressed or infested with diseases or insects.

Purchase as close to planting day as possible, but be sure that plants that can’t tolerate frost aren’t planted too soon. Our frost-free date (central New Jersey) is usually near May 10. Each year varies. Don’t be so eager to get an early start that your plants will be damaged or killed by late frosts. Be prepared to cover those that may be threatened.

On an overcast day, planting can be done anytime. On a sunny day, transplant the seedlings in early morning or late afternoon so midday sun doesn’t damage them.

After removing the plants from their container, check the root system. If the roots are tightly massed and take the form or the pot, they must be cut slightly or loosened a little so they will be able to grow into the surrounding soil.

Set the plants in the ground at the same depth they were in the pot and settle soil around them gently, being sure not to leave any air pockets around the roots.

Water thoroughly. Some gardeners use a transplant solution of water-soluble fertilizer, compost tea, or liquid seaweed mixed according to the label to reduce transplant shock.

Form and Flower:  A pleasing combination of alyssum and plectranthus blends the white margins of the Plectranthus with the tiny white flowers of Alyssum. The textural contrast between the two plants makes this pairing particularly charming . (Photo by Kathy Enquist)

How to Care for Annuals

WATERING: All plants need water to grow. For most annuals, watering at the rate of one inch of water per week will be enough. Use a rain gauge to determine how much rain has fallen, and reduce watering accordingly. Some plants, such as California poppy, are content with less water. When irrigating, water thoroughly, preferably in the morning. Frequent, shallow sprinkling encourages shallow root systems and disease development.

MULCHING: Using organic mulches, such as grass clippings or shredded hardwood, or inorganic mulches, such as black plastic or polyethylene weed barrier, helps to maintain even soil moisture and temperature and  deters weeds. Be sure to use a little extra fertilizer (complete analysis, such as 10-6-4 or 10-10-10) when using woodchip mulches to offset the nitrogen used up in the decomposition process. Sometimes, organic mulches harbor pests such as earwigs and slugs, but this disadvantage is usually offset by the advantages of mulching.

PINCHING AND SHEARING: Some annuals, such as sweet alyssum and lobelia, benefit from pinching their tips to encourage branching or to maintain form.

Zinnia are among the annuals that benefit from deadheading, which will help the plants remain attractive, keep them from going to seed, and increase flower production.

DEADHEADING: Removal of spent flowers to keep plants productive and to maintain an attractive appearance is called “deadheading”. Marigolds, zinnias, calendula, and others benefit from this form of pruning. Do not deadhead from early September on if seed dispersal is desired for self-sowing or if seed is going to be harvested.

SIDE-DRESSING: Annuals grow rapidly in order to complete their life cycle in one growing season. In late June or early July, applying a second application of fertilizer near, but not on, the plants, gives them a boost. Follow label directions for how much to use.

STAKING: Taller annuals, such as snapdragons and African marigolds, benefit from added support so heavy rain and wind don’t knock them over. Tomato cages, bamboo and metal stakes, are among the forms of support that can be used to keep plants upright.

Annual sunflowers are a great addition to beds and borders. Their big, daisy-like flowers come in a variety of colors and sizes–some that tower over 16 feet in height, while others are better suited for smaller spaces and containers.

PEST CONTROL: Pests take many forms: weeds; insects; fungal, viral, and bacterial diseases; mites; mollusks (slugs); and animals. Luckily, pests don’t usually bother most annuals. Take care to keep weeds out of the flowerbed to avoid competition for available nutrients and water, especially while plants are small.

Most pest problems can be solved or controlled without the use of toxic chemicals.  Before reaching for pesticide sprays , consider one of the many cultural, biological, or mechanical means at your disposal. Chemical attack should only be used as a last resort when other methods fail.  The best defense against garden pests is keeping plants strong  healthy, and protected by natural enemies.  Consider the following for creating good growing conditions for your plants and unfavorable conditions for pests:

  • When buying annuals, look for disease-resistant varieties.
  • Be careful not to under or over- watering–both make plants vulnerable to insects and diseases.
  • Change the location of your annuals  from year to year–this helps to disrupt the life cycle of pests.
  • Plant a variety of plant species — which will lessen overall damage should a pest gain a foothold and also provide welcome habitat for beneficial insects that can keep garden pests in check.

If pest problems still arise, we’re here to help! Consult with a Master Gardener from Rutgers Cooperative Extension by calling our Garden Helpline at (609) 989-6853.

Need a Little Annual Inspiration?

Looking for some ideas for adding annuals to your own garden? Visit the Annual Garden at the Mercer Educational Gardens in Pennington.  Each year Mercer County Master Gardeners select a new slate of annuals to grow from seeds and plugs.  So come out and visit us –you may walk away with some fresh ideas for plants and combinations you might not have thought of before…

A glimpse of the annual garden at Mercer Educational Gardens in Pennington, NJ. Each year Rutgers Master Gardeners of Mercer County set out to create new color combinations and textures to bring to life two large garden beds composed entirely of annuals.

More information:

ANNUAL PLANTS FOR THE GARDEN, Barbara J. Bromley, Mercer County Horticulturist

ANNUALS FOR DIFFICULT SITES Barbara J. Bromley, Mercer Co. Horticulturist 2015

ANNUALS FOR HEAT AND DROUGHT, Barbara J. Bromley, Mercer County Horticulturist

PLANTING HIGH VISIBILITY FLOWER BEDS Barbara J. Bromley, Mercer Co. Horticulturist

BASICS of FLOWER GARDENING Barbara J. Bromley, Mercer County Horticulturist

 

Ready, Set, Plant! Tips for getting your garden off to a great start

Stacks of lush spring plants are hard for just about any gardener to resist!  Before buying, don’t forget to read plant labels and make sure conditions in your garden and the plant’s cultural requirements are a match. (Photo by Joe Scarlata)

Plant sales abound this time of year and whether you’ve been shopping at neighborhood  plant swaps or browsing through local nurseries — you know how energizing the experience can be. But once you arrive home,  do you ever find yourself saying, “Now what?”  If so, we’ve got you covered!  We love plants sales too, so we’ve put together a few Master Gardener “Tips of the Trade” that will have you digging in to this– the most optimistic of garden seasons–with excitement and confidence.


It’s planting time!  The frost free date in central New Jersey is on or after May 10 –so now’s the time for gardeners to get growing.


Ready or not: What to do if planting’s on pause…

If you’re NOT planning to transplant your new plants immediately,  remember to water them as needed and protect them from animals and harsh elements such as frost and wind until you are ready to plant them.

For the best results for all of your garden plants–as well as your lawn–you should know the pH and nutrient level of your soil.  To do this, have a soil test run.  You can stop by the Extension Office to purchase a soil mailer, or call the Extension Office at 609‑989-6830 for more information.

Planting  101: Steps to help your new plants thrive

The following tips apply to most newly-purchased plants.  But, be sure to check plant labels first for any variety-specific instructions.

SITE CONSIDERATIONS: Read plant labels carefully before selecting planting sites. Plants have different requirements for sun/shade, soil condition and drainage.

Individual annuals and perennials have different requirements for sun, shade, partial sun, soil quality, and drainage. When deciding what plant to put where, also consider a plant’s mature height and whether you will you be able to see and enjoy it among its garden companions. (Photo by Joe Scarlata)

Also, since plants have different growth patterns and rates of growth, consider the spread and the height of the plant at maturity.

In addition, two other factors should be considered:  visibility (planting in order for the plant to be seen and enjoyed) and accessibility (planting in order to for the plant be accessible for fertilizing, dead heading and/or pruning).

Make sure to remove weeds and debris before planting. It’s also a good idea to add some organic matter–like compost –into the soil to help new transplants thrive.  (Photo by Theodora Wang)

SOIL PREPARATION: Remove all weeds and other debris from the planting site.  Loosen soil for good root growth and mix in organic matter (compost, well rotted manure or peat moss) to amend the soil. If a recent soil test was performed, refer to the report for information regarding recommended lime and fertilizer. If no soil test has been done, fertilize with 10-10-10 at 2 lb. per 100 square feet, or follow the label directions on a fertilizer for flower or herb gardens. Spade or rototill amendments to a depth of 6-8 inches for most annuals or perennials.

The best time to install your plants is on a cloudy day, which reduces the chance of sun and/or heat stress on new transplants. (Photo by Joe Scarlata)

PLANTING: Hardy perennials, trees and shrubs can be planted immediately. (The frost-free day in central New Jersey is on or about May 10.) If tender plants– aka annuals– are threatened by frost, be prepared to cover them.

Plant at any time on a cloudy day, or early morning or late afternoon on a sunny day.  Prepare a space at least twice the size of the plant container and almost as deep. Remove the plant from the container and loosen or cut the roots slightly to encourage growth. Plant at the same depth as the plant was in the container. Gently settle soil around the roots, being careful not to leave air pockets around the roots.  Water thoroughly.

MAINTENANCE: Water early in the morning (preferable) as plant species require. Use a rain gauge to determine how much rain had fallen and adjust watering schedule accordingly.  Mulch will help maintain soil moisture, temperature and deter weeds. Mulch depth should never exceed two inches.

GARDEN HELP: For more planting information, or if you are having plant, tree or lawn problems, please call the MASTER GARDENER HELPLINE (609-989-6853), Monday through Friday from 9:00 a.m. to 3:00 p.m. You can also visit our website at www.mgofmc.org for more information from the Rutgers Cooperative Extension and Barbara J. Bromley.

Looking for inspiration? Stop by Mercer County Educational Gardens which feature a variety of beautiful plants– all of which are proven to thrive in our area. (Photo by Joe Scarlata)

GARDEN INSPIRATION: Don’t forget to visit our Educational Gardens  this summer when the gardens are in their full glory, the flowers are in bloom and the butterflies are visiting.  For information about coming activities, check out our Events page.

Happy planting!


More info:

Basics of Flower Gardening

Planting High Visibility Flower Beds

10+ Most Common Gardening Mistakes

 

2017 Plant Expo


Rutgers Master Gardeners of Mercer County wish to thank everyone who supported our annual plant sale!  We hope the plants you purchased are beautiful additions to your garden and that you enjoy them as much as we have enjoyed bringing them to you!


Master Gardener Plant Expo 2017


This year’s sale day is sure to be fun for seasoned gardeners and novice gardeners alike!

The plant sale will feature the ever-popular Rutgers Master Gardener home-grown perennials, trees and shrubs and a garden market of plant material sold by selected top-notch nurseries from New Jersey and Pennsylvania.

This is a unique opportunity to talk with vendors and purchase a wide assortment of native plants, woody ornamentals, perennials, herbs, annuals and tropical plants. This year we will welcome a new local vendor featuring certified organic plants. Tomatoes, tomatoes, tomatoes (Rutgers varieties and heirlooms) as well as many hot pepper varieties will be in abundance.

Mercer County Horticulturist Barbara J. Bromley will be answering gardening questions and Rutgers Master Gardeners will be on hand to help choose the right plant for the right place.

Click here for a scalable map and location guide:

2017 Plant Expo Map

Plan to come early for best selection and stay to enjoy every aspect of Expo. This event will be held rain or shine and there is plenty of free parking. Credit cards, personal checks and cash are accepted at the sale.

Check out some of this year’s selections below: 


Home-Grown Plants

Master Gardener-grown plants are the most popular part of Plant Expo!

People line up very early to get the best selection of home-grown perennials, trees and shrubs and return year after year to check out the selection. Whether you have a shade garden or a sunny butterfly garden, you can find something of interest in the Home-Grown area. Of course, there is no guarantee that every variety will be available on sale day but there will be a wide assortment of plants.

Click below for list of home-grown plants for this year’s sale:

2017 Plant Expo Home-Grown Plant Selections


Jersey Tomatoes!

Home-grown tomatoes and peppers will be in abundance, including the popular Rutgers tomato varieties, Rutgers, Ramapo, Moreton, Rutgers 250, KC-146 and Rutgers 39. Rutgers Master Gardener Bruce Young has started the tomatoes and peppers from seed for the sale and has potted up over 1,000 tomatoes. Along with the Rutgers varieties of tomatoes there will be lots heirloom varieties. Patio, cherry, and plum, to name a few types, will be available for purchase. Popular and some different Hot pepper varieties will be offered.

Click below for list of tomatoes and peppers being grown for this year’s sale:

2017 Plant Expo Tomatoes 

2017 Plant Expo Peppers

We will try hard to have each variety listed available on sale day but there are no guarantees!


Select Local Plant Vendors

Our hand-picked plant purveyors offer a variety of plants uniquely suited for local gardens.    

This is a unique opportunity to talk with vendors and purchase a wide assortment of native plants, woody ornamentals, perennials, herbs, annuals and tropical plants. This year we will welcome a new local vendor featuring certified organic plants.

To view a list of our select group of local plant purveyors, click here: 

2017 Plant Expo Vendors


Second-Hand Sale 


The ever popular Second-Hand Sale of garden-related items will be back this year. Pots galore, baskets and books to name a few, will definitely be available this year.  There are always a few surprises and you really never know what treasure you might find.