Time to Start Tomato Seeds Indoors Along the Front Range Colorado

Quick to germinate and grow, tomato seeds are best sown indoors about six weeks before the average last frost date. People in the Denver metropolitan area normally use Mothers' Day as a guide for when to plant. However, Denver had its last spring freeze on April 5 in 1977 and on June 8 in 2007. The average over the last ten years is May 5. Using May 13, 2018 Mothers' Day as a planting date, tomato seeds can be started indoors the first week of April.

Here's a great guide on starting tomato seeds indoors from Modern Farmer: 

How to Grow Your Own Tomatoes, Part 1: Starting Seeds Indoors https://t.co/uApuVaugUX pic.twitter.com/DRJDAJ8fKR

— Modern Farmer (@ModFarm) March 10, 2018

Colorado State University Vegetable Planting Guide. 

Best Practices for Starting Seeds

Photo Ft. Collins Nursery

IIt’s the time of year when many gardeners begin to start seeds indoors for their vegetable gardens. John Porter with Nebraska Extension and Nebraska College of Technical Agriculture has this advise about starting seeds indoors:

Be economical. Use low-cost or recycled items such as takeout containers or shallow disposable aluminum baking pans to start your plants.  Sterilization is key in reducing disease.  Thoroughly wash containers, then dip in a solution of 10% household bleach (1 part bleach : 9 parts water) to disinfect.

Start seeds in clean, sterile seed-starting mix. Don’t skimp. Use a sterile mix that is primarily made of peat or coconut coir.

Transfer the seedling to an individual container/cell/pot with regular potting soil (when its first set of true leaves (the second leaves appear).

Place newly sown seeds in a warm (around 70 degrees F) place to help

them germinate faster. Heat is the most important factor in seeds

germinating: Move the seedlings to a cooler place (around 65 degrees) as

they will grow sturdier and not get thin and leggy.

Light is necessary for good plant growth. A good, sunny (usually south 

facing) window with plenty of light is one option. Otherwise invest in some lighting.

Don’t get started too early.  Read the packet for the number of days/weeks before last frost to start your seeds.

What about fertilizer? Seedlings don’t need much in the way of 

fertilizing when they’re put in a good potting mix.

For the complete article, check here: Starting Seeds with Success: Best Practices.

Plant Talk Colorado Starting Seeds Indoors.

Colorado State University Vegetable Planting Guide.

Photoperiodism: March Word of the Month

Photo courtesy maximumyield.com

Photoperiodism: the amount of light and darkness a plant is exposed to.

This is the time of year when we make the transition from more darkness to more light in the Northern Hemisphere (the spring equinox). The spring equinox brings the transition of seasons, as the balance of light shifts to make for longer days, shorter nights, and a shift in photoperiodism for plants.

Photoperiodism causes a biological response to a change in the proportions of light and dark in a 24‐hour daily cycle. Plants use it to measure the seasons and to coordinate seasonal events such as flowering. Photoperiodism is important for plants as the amount of uninterrupted darkness is what determines the formation of flowers on most types of plants!

"Short day" (long night) plant requires a long period of darkness. They form flowers only when day length is less than about 12 hours. Many spring and fall flowering plants are short day plants. Examples are: chrysanthemums, poinsettias, Easter lilies, and some soybeans

"Long day" plants require only a short night to flower. These bloom only when they receive more than 12 hours of light. Many of our summer blooming flowers and garden vegetables are long day plants. Examples include: spinach, radishes, lettuce, and irises.

"Day neutral" plants form flowers regardless of day length. Tomatoes, corn, cucumbers and some strawberries are examples.

For more information about photoperiodism and its effects on plants, check out these links:

What are Short day and Long Day Plants. 

Daylight Photoperiodism and Onions. 

March is the Time to Plant Pansies by Carol King

March is the perfect time to plant pansies. Pansies and violas or Johnny jump-ups can be staples of the spring garden. These plants, both from the genus Viola, prefer cooler weather and can survive temperatures into the 20s, and don’t mind spring snows!

Pansies have a colorful past with lots of folklore about them.  One of my favorites is this one about why they have no odor: “A German fable tells of how the pansy lost its perfume. Originally pansies would have been very fragrant, growing wild in fields and forests.  It was said that people would trample the grass completely in eagerness to pick pansies. Unfortunately, the people’s cows were starving due to the ruined fields, so the pansy prayed to give up her perfume. Her prayer was answered, and without her perfumed scent, the fields grew tall, and the cows grew fat on the fresh green grass.”  {from Wikipedia).

Soil Testing: CSU Extension or DIY?

Photo by Donna Duffy

One of the first recommendations that we make as master gardeners is to have your soil tested before you add any amendments, plant anything or take any action at all in your home garden. This is probably the most important step any gardener can take before planting that first seed. The "blue chip" soil test is done at a Cooperative Extension soil testing lab such as the one at CSU.

However, we know that realistically, many home gardeners utilize a "do it yourself" soil testing product from their local garden centers.

So how do those testing kits stand up against the "real deal" at the Soil, Water and Plant Testing Laboratory at CSU? 

Winter Desiccation of Evergreens

Winter desiccation, photo courtesy Purdue University

It’s been a typical Jefferson County winter with periods of warm, windy, low-humidity days with no snow cover and extended dry periods. This contributes to “winter desiccation” on needled and broadleaved evergreens. Last year’s transplants are especially prone to winter desiccation (also called winter burn) under these conditions.  As the plants hold their leaves, they continue to transpire which becomes difficult during warm, dry winter periods. Below ground, small “hair roots” may die in dry soils leaving roots unable to replace lost leaf moisture.

How to Read a Seed Packet by Paula Hamm

Photo by Paula Hamm

Growing plants from seed is incredibly rewarding and fascinating but there are a few things you need to know before you get started.  You can find nearly everything you need to know on the seed packet itself.  

First, every seed packet should list the common and Latin name of the seed inside the envelope.  It is not uncommon for more than one plant to have the same common name;  the Latin name can help you figure out whether the seed packet you are holding has the seeds you want.

What Happens to Insects During the Winter?

Lady beetle on Asclepias speciosa, photo by Donna Duffy

Do you ever wonder what happens to insects over the winter months? What conditions allow them to survive? Why do some die and some overwinter? What beneficial and pesky insects will show up in my landscape this spring? Planttalk Colorado offers the following information on Insect Overwintering to help you answer these perplexing questions. 

Not So Fast! Gardening Tips for Late Winter

Pulsatilla patens (Pasque flower) 

Yes, it does feel a bit like Spring outside. And yes, there are signs of life in your yard and garden. As tempting as it is, don’t go full-force into your gardening mode quite yet. Following are some gardening chores you can start right now, and others that you’ll need to wait to begin.

Care for African Violets by Vicky Spelman

Photo Elaine Lockey

African violets can be a great indoor plant for Colorado. Their care is fairly simple and they will bless you with beautiful blooms. Here are tips for their care:

• Light: Moderate to bright, indirect, indoor light.
• Water: In general, African Violets need just enough water to keep the soil moist, but never soggy and should be room temperature. They have self-watering pots - a smaller pot with the violet sits in a larger pot that has a water fill line and when nearly empty refill.
• Fertilizer: Your fertilization practices can also impact how well African violets bloom. Unlike plants that grow outdoors, houseplants are totally dependent on the grower to apply sufficient nutrients without overdoing it. The small pots these plants are typically grown in do not maintain a large reserve of nutrients. If you do not fertilize them on a regular basis, they may not have the necessary nutrients to spend on flowers. On the other hand, too much fertilizer with high nitrogen content can lead to lush foliage at the expense of flowers.
• Other tips: Pinch off spent blossoms and blossom stems to encourage development of new blooms. Place plants away from floor vents, fans, or entrance doors to avoid air drafts and bursts of cold air.

For additional information: 

African Violet http://planttalk.colostate.edu/topics/houseplants/1301-african-violet/

Why Isn’t my African Violet Blooming. https://extension.psu.edu/why-isn-t-my-african-violet-flowering.

Low Humidity in House Plants by Carol King

Plants on Pebble Tray. Photo the-news.co

This time of year, Colorado gardeners turn to indoor plants to soothe our gardening souls.  However the indoor environment in our homes can be very harsh for many plants. Many house plants are native to humid, tropical rain forests and require special consideration when they reside in Colorado homes. While lighting and temperatures need to be monitored for successful indoor gardening, humidity is the big issue during colder months.  Heating systems common in Colorado circulate dry, warm air throughout the house. Our indoor environment often has less than 10 percent humidity. This is a drastic reduction from the 70 to 90 percent relative humidity levels found in the native climates of most tropical plants.

Why does this matter? Humidity is the level of moisture in the air and can affect a plant's need for water.  Plants grown indoors with low humidity lose more water through transpiration, so their root systems require more water. In addition, plants located near heating or cooling vents may develop leaf spots or brown tips.

Here are a few tips to help alleviate low humidity problems:

• Misting plants may help alleviate this condition, however, it must be done frequently to be effective, and it may promote some foliar diseases. 
• Place several plants together on a tray filled with gravel. Filling the tray with water provides the humidity many plants need. Make sure the bottom of the container does not stand in water; the soil will become water-logged and cause root damage. 
• Use a humidifier around your plants. 
• For house plants with moderate humidity needs, group them together during the heating season. Each plant gives off humidity through transpiration. Clusters of plants will create very good humidity in the surrounding air.

For more information see this:  http://planttalk.colostate.edu/topics/houseplants/1317-houseplants-temperature-humidity/

Keeping Roses Healthy During Winter

Rose canes greening up in Lakewood - January 22, 2018

Have you taken a look at your roses lately? This warm winter has created conditions for the canes to green up very early. It’s way too early to prune them! Instead, check to make sure your mulch layer is still intact, and add more if you’ve lost some to wind or critters.

The following information from the Denver Rose Society gives tips on rose care during these late winter months.