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I hope you all enjoyed the holiday season. Here’s to a wonderful 2025 with new gardening adventures as we grow together.

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VIDEO OF THE WEEK:
Home Hydroponics
(K-State Garden Hour December, 2024)

Grow fruits and vegetables year-round with home hydroponics. Learn the basics of hydroponics with Shawnee County Horticulture Agent, Lane Wiens.

Horticulture Newsletter 2024 Indexed
All of the articles published in the 2024 Horticulture Newsletter have been indexed according to subject. Lori Dickey has undertaken the time-consuming task of linking all of the articles in one document which can be found at the Horticulture Newsletter website. Thank you, Lori!
Horticulture Newsletter Website
VEGETABLES
Extension Master Gardener Tomato and Pepper Variety Trial Report
Many of our K-State Extension Master Gardeners participated in the 2024 Tomato and Pepper Variety Trial project. Each participating county was required to grow 11 varieties of tomatoes, 14 varieties of sweet peppers and 13 varieties of hot peppers. The recorded growth data and made evaluations throughout the growing season. The following report highlights the procedures followed and a summary of the results.

2024 Master Gardener Tomato and Pepper Variety Trial Report

Starting Onions Indoors
If grown from seed, onions need to be started indoors 10 to 12 weeks prior to the transplant date. Onions are typically planted in mid- to late-March to avoid the summer heat. Place seeds ½ to 1-inch apart in a tray filled with seed-starting media. Keep the tray in a warm location (75-80 degrees F) until seeds germinate. When the seedlings are one to two-inches tall, move the tray to a cooler location (60-65 degrees F). Provide adequate light and use a water-soluble, general-purpose fertilizer no more than once per week when seedlings reach two to three inches in height.

Starting Garden Transplants from Seed
It’s not too early to begin gathering seeds for the spring garden. Select seeds from reputable sources to ensure high quality, healthy seeds.

Starting transplants for the vegetable garden typically requires four to eight weeks from seeding to transplant date. Visit the Kansas Garden Guide where you can find the Average Expected Planting Calendar to know when the best start date is for seedlings intended for transplanting into the garden.
Always use a disease-free, soilless planting media or seed-starting mix for seeds. The containers for seed-starting can be individual cups, trays or even recycled containers as long as they have drainage holes in the bottom. Fill the container with a couple inches of media and then lightly cover the seeds with the mix after planting. Keep the soil moist until the seeds germinate and keep the containers under lights in a warm location.
When the seedlings have grown two to four small leaves, they are ready to be transplanted into small pots. This will allow them to continue growing until it’s time to transplant into the garden.
It’s important to give plants time to harden off before transplanting. This should typically be started about ten days before the transplant date and involves gradually acclimating the seedlings to the outdoor conditions by reducing the amount of water the plants receive while slowly increasing their exposure to the outdoor conditions. This prevents the plants from experiencing transplant shock so they can continue normal growth when they are transplanted.

FLOWERS
Forcing Paperwhites
A member of the Narcissus genus, paperwhites are spring bulbs that are easy to force into bloom. Begin with healthy bulbs from a reputable source. Store bulbs in a cool, dry location until planting.

Choose a clear, shallow dish (approximately three-inches deep) that does not have drainage holes. Add a one-inch layer of washed gravel or decorative stones to the base. Place the bulbs on top of the rocks and use additional gravel or stones to hold them in place. The tops of the bulbs should remain visible. Fill the container with enough water to keep the base of the bulbs wet.
Keep the container in a cool, dark location initially to promote root growth. Then move it to a south-facing window until the bulbs begin to bloom. Keep flowers in a cool location away from direct sunlight to prolong the bloom period. Paperwhites can be expected to bloom within 8 weeks of planting.
Important Notes:
Maintain the water level at the base of the bulbs throughout their growing period.
Paperwhites can be forced in a moist, soilless mix as well. Use a container with drainage holes and plant the bulbs so the top third is visible.
Paperwhite bulbs should be placed within one-inch of each other in the container.
The linear leaves of paperwhites often fall over. They can be propped up with decorative supports or grown in a taller, glass container to hold them upright.

MISCELLANEOUS
Monitor Indoor Plant Temperatures
Now is a good time to check on houseplants to ensure they aren’t getting too cold. Plants next to windows or near exterior doors are at the greatest risk. Many houseplants including: Chinese evergreen (Aglaonema), flamingo flower (Anthurium), croton (Codiaeum), false aralia (Dizygotheca), and ming and balfour aralia (Polyscias) are highly sensitive to cold temperatures.
Most houseplants prefer temperatures above 50 degrees F though some require the temperature to be over 60- or 65-degrees F. If necessary, move plants away from the windows or door entrances to reduce cold temperature exposure.
QUESTION of the WEEK
Pruning Pyracantha
We have some giant pyracantha shrubs that are about 10 years old. They are doing great and are low maintenance but are getting to the edge of the planter boundary and encroaching on the sidewalk bordering it. Will they tolerate heavy pruning? What time of year should that be done?
In general, it is recommended to remove no more than one-third of the shrub when pruning. However, pyracantha can tolerate a heavy “rejuvenating” pruning as needed. Plants can be cut to about 6-inches from the ground in early spring before new growth begins.

Contributor:
Cynthia Domenghini, Instructor and Horticulture Extension Specialist

Division of Horticulture
1712 Claflin, 2021 Throckmorton
Manhattan, KS 66506
(785) 532-6173

For questions or further information, contact your local extension agency.
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K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. If you have special requirements due to a physical, vision or hearing disability, or a dietary restriction please contact Extension Horticulture at (785) 532-6173.

Cynthia Domenghini, Ph.D.
Instructor; Horticulture Extension Specialist
Department of Horticulture and Natural Resources
Kansas State University
1712 Claflin Rd.
Manhattan, KS 66503
785-340-3013
[email protected]

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Onions, many other vegetables need time to germinate before spring planting.

Spring gardens may seem distant in the midst of winter, but Kansas State University horticulture expert Cynthia Domenghini says it’s not too early to begin gathering seeds for the coming season.

In fact, many vegetables need to be started in January if gardeners intend to transplant them to the outdoor garden in March or April.

“Transplants for the vegetable garden typically require 4-6 weeks from seeding to transplant date,” Domenghini said.

Onions take longer, as much as 10-12 weeks. Domenghini said guidelines for vegetables commonly grown in Kansas are available in the Kansas Garden Guide, available from the K-State Research and Extension bookstore.

Look for the Average Expected Planting Calendar to determine when to start vegetable transplants.

For most vegetables, Domenghini offers the following tips for starting transplants indoors:

• Always use a disease-free, soilless planting media or seed-starting mix for seeds. The containers for seed-starting mix can be individual cups, trays or even recycled containers as long as they have drainage holes in the bottom.
• Fill the container with two inches of media and lightly cover the seeds with the mix after planting. Keep the soil moist until the seeds germinate, and keep the containers under lights in a warm location.
• When the seedlings have grown 2-4 small leaves, they are ready to be transplanted into small pots. This will allow them to continue growing until it’s time to transplant them into the garden.

“It’s important to give plants time to harden off before transplanting,” Domenghini said. “This should typically be started 10 days before the transplant date, and involves gradually acclimating the seedlings to the outdoor conditions by reducing the amount of water the plants receive, while slowly increasing their exposure to outdoor conditions.”

Starting onions indoors

Onions are typically planted in late March to avoid summer heat, so if growing them from seed, the plants need to be started 10-12 weeks before transplant date. That means as early as mid-January.

To start onions indoors, Domenghini suggests:

• Place seeds ½ to 1 inch apart in a tray filled with seed-starting media. Keep the tray in a warm location (75-80 degrees Fahrenheit) until seeds germinate.
• When the seedlings are 1-2 inches tall, move the tray to a cooler location (60-65 F).
• Provide adequate light and use a water-soluble, general-purpose fertilizer no more than once per week when seedlings reach 2-3 inches in height.

Domenghini and her colleagues in K-State’s Department of Horticulture and Natural Resources produce a weekly Horticulture Newsletter with tips for maintaining home landscapes and gardens.

Interested persons can subscribe to the newsletter, as well as send their garden and yard-related questions to [email protected], or contact your local K-State Research and Extension office.

Houseplants are fun to have year round. They do have care requirements to keep them happy and healthy. One of these requirements is nutrition. Houseplants should not be fertilized with a consistent amount of fertilizer throughout the year. The amount required depends on the season. Normally houseplants that rely on natural sunlight are not fertilized at all from November through February as the light levels are so low that fertilizer is not needed. The light intensity is less during the winter as the sunlight must pass through more of the atmosphere resulting in less light energy. Also, the days are shorter resulting in even less light available for growth. Fertilizing during these dark months can do harm. Fertilizer are salts and can build up in the soil if the plant doesn’t take them up due to slow growth. Eventually the fertilizer salt content can reach a level that roots are burned.

So, what is a simple method for fertilizing houseplant? Fertilize at the rate recommended on the label of your fertilizer from March through October. Don’t fertilize at all during November through February unless the plants are receiving supplemental lighting. If they are, then fertilize the same amount throughout the year.

If your fertilizer recommends fertilizing once a month, try splitting the concentration recommended in half and fertilize twice a month. The total amount is the same but the frequency is doubled which may result in a more efficient use of the fertilizer.