Top Ten Best Management Tips for Starting Your Garden from Seed

One of the oldest horticultural practices in the world is seed starting.  Real gardeners know that you never stop thinking about or putting into practice, your garden.  The catalogs have arrived, you have dog-eared your pages, made your lists and ordered your seeds and they are now arriving.  So now, the plans begin for what you will start indoors and when. 

Since the cool season vegetables and annual flowers can be planted directly in the garden when soil temps permit, it is the warm season plants you should be scheduling.  These plants need warmer soil temps to germinate, and in our 100-120-day average growing season, they need a little “head start” indoors before heading outside to complete their production.   Seed packets are the “go-to” for instructions as to when each variety should be started indoors, but rule of thumb, with few exceptions, is 6-8 weeks before the last average frost date for your area.  Here, in our zone, the smart gardener shoots for mid-May to first of June for putting out their precious transplants.

We all adapt our gardening practices to suit our needs as we become more accomplished.  However, there are some tried and true practices that will guarantee success for the beginning seed starter.  When things don’t work out, always go back to the following practices to sort out your issues and you will have a great start to a successful garden year. 

Courtesy Megapixl.com

1.       Seed - Start with clean, fresh seed.  Explore the wondrous variety of each vegetable or flower you plant by checking out the offerings of the seed companies, either online or by catalog.

Courtesy:  Adventures of Mel

Green leaf lettuce is great, by why not try Strawberry Cabbage lettuce, or Drunken Frizzy-Headed Woman lettuce, or deep burgundy Merlot lettuce.  Try the Easter Egg collection of radishes and Dragon Tongue Beans.  Obviously, plant what your family will eat, but check out all the amazing possibilities in each variety and try at least one new thing each year to add diversity to your garden.
 

2.       Equipment – You do not need to spend a fortune to garden.  Be creative and re-purpose items to start your seeds– just think outside the box.  You’ll need a container of some kind to plant in, a tray to capture moisture, a “lid” to create a terrarium effect during germination.  There are many possibilities of seed starting trays to purchase, that make the activity both easy and safe.  But you can re-purpose yogurt cups, paper cups, deli containers, plastic fruit boxes (they even come with their own lid) to name a few, just make sure you add proper drainage.  If you re-use old plastic pots or any other container, make sure to sterilize them and air dry them before planting. 

Courtesy:  Lovelygreens.com

3.       Planting Medium - The more sterile the medium, the better your success.  This is not the place to use garden soil, or even potting soil.  Go for a seed starting mix, sometimes called germination mix.  These have no soil at all, but is a mixture of peat moss, vermiculite and/or perlite.  It is sterile and light weight to allow for the tiny plants to send roots out easily and avoid any soil-borne diseases that might attack your little plants. 

4.       Planting Depth – This is one of the biggest rookie mistakes.  Always check the seed packet for the planting depth.  A large percentage of seeds are so tiny, that correct planting depth is actually ¼”.  In this case, seeds should be placed on the top of moistened, unpacked soil and then a quarter inch layer of medium sprinkled on top, much like a chef would sprinkle salt to season food.  Then a very gentle one finger tamping over the seed to create seed to soil contact – no packing down at all. 

5.       Germination – To germinate properly, seeds need warmth and moisture.  The correct steps are as follows:

(a)The best procedure for planting seeds is to moisten the germination mix prior to starting.  The medium should be moist, but never wet.  You should be able to scoop up a fist full.  Squeeze and the ball should hold it’s shape, but when dropped from a 2to3 -foot height back into the container, it should break completely apart.  So, damp/dry is the term.  Fill each container or cell and tamp on the table to settle – never press or pack the medium.

(b) Sprinkle or spread the seed on top.  Remember to read the packet for the correct dept.  Larger seeds may need to be planted at ½” so you could make a small hole for these. 

(c) Cover the seed with the correct amount of medium

(d) Add a bit of moisture with a spray bottle – not a watering can

(e) Cover with a lid and place in a warm spot.  You will want a terrarium effect to happen over the next day or so.  Following all the above instructions should prevent you from having to add water during the germination phase.  The terrarium should do it.  If this does not occur, you likely did not have your medium moistened properly.  You may need to open the lid and spritz with warm water to create adequate moisture. 

(f) Again, consult the seed packet as to when to expect your seedlings to germinate, so you know if all has gone well.  Once they have germinated, the lid should be removed, and lights added. 

6.       Lights – Very few species of plants require light to germinate (again – the seed packet will give you this information if required).  So, once your seeds have germinated, it’s time to add light.  Although possible to use window light, here is the only place where I would suggest you invest some money.  A simple shop light casing with a T-12 Cool Ray and a Warm Ray bulb will easily do the trick.  However, the newer LED T-8’s are 50% more efficient.  Lights should be approximately 2” from the top of the seedlings at all times, so you need to be able to adjust as the seedlings grow.  Lights should be on 14-16 hours per day and there should be 8 hours of darkness for proper growth.  An inexpensive timer helps here.

Courtesy:  Home Depot

7.     Warmth - warmth added from below throughout germination and the 8 weeks of growth is recommended.  There are plant heat mats that can be purchased, or you can re-purpose old heating pads with temps set on low. 

8.       Air – It is helpful to add some movement and air circulation once your seedlings are about 3-4 inches high.  Good air circulation will help keep moisture off the surface of the soil and the leaves as well as strengthening the stems.  The goal is short and bushy, not tall and leggy. 

9.       Watering and Fertilizing – Water when soil is nearly dry, but never dry all the way.  Never wet either.  Watering from the bottom tray is recommended to keep moisture off the tender leaves. 

You can begin fertilizing when the first set of true leaves are established.  This will be the second set you will see, the first being the cotyledon leaves.  Use any liquid fertilizer of your choice at one quarter strength. 

10.   Become a Good Planner and Record Keeper - There is no substitute for good record keeping.  Thomas Jefferson is a premier example of good garden planning and record keeping with his meticulous notes.  If he can do it, so can you. For great suggestions, check out the January 30 post on this blog by Linda Langelo on great record keeping tips. 

This is a great time of year to find a good class on seed starting near you.  For the best science- based information, as well as any questions about starting your garden from seed, contact your local CSU Extension office.

By Patti O’Neal, Horticulture and Food Systems Coordinator, CSU Extension, Jefferson County.

The Simple Trials of Seed Germination

Posted by: John Stolzle, Jefferson County Extension

Despite the lingering winter weather, spring is on its way. And though it may yet be just a little too early for preparing flowerbeds, raised gardens and the like, now is a great time to test the germination potential of any seeds which you may have saved in seasons past.

Seeds from leftover packets or harvested from a previous year’s crops can remain viable for many years when stored under the right conditions (CSU Factsheet on storing seeds).

If you do not have any seeds from last year, you might consider saving some this season. Seed swaps and seed saving courses are becoming popular, and carrying over seeds between years can be a fun to way to maintain continuity between multiple growing seasons. For further reading on this topic, I might point you to 'this' seed saving blog post.

Generally, vegetable seed packs sold in Colorado are required to germinate above a mandated minimum percentile, although the relative longevity of these seeds can vary. Storage conditions (for example, temperature and humidity) can affect the viability of leftovers, or seeds gathered at the end of a previous season. A quick and simple test can help to assess how your seeds are doing.

I’ve been running some seed germination experiments and would like to share the process and some results.

Overall, the methods are simple: Place 10 (or more) seeds on a damp paper towel, roll/fold up the paper towel, and check it every few days. Some additional tips and tricks are presented below.

Step 1: Seed Selection

Discard any broken, crushed, or otherwise damaged seeds.

Step 2: Preparation
To help prevent contamination, clean off a countertop or other workspace as best you can, and wash your hands. A paper towel or two can act as buffer between the “germination paper towels” and a worktop. 

Lay out two connected paper towels and then wet them with water (I used distilled water). Next, place your seeds in rows on the bottom portion of the two paper towels (image B.) - this will aid in later counting. For the most part, the more seeds you use, the more robust your results will be. In the photos, I was testing ‘ancient’ seed packets and therefore used many seeds, but 10 or so should suffice for a quick assessment.

Following seed placement, horizontally Fold Down the upper portion of the two paper towels (Image C).

Tip. 2-ply paper towels were used in these tests, they held up fairly well.

Step 3: Seed Placement & Folding

In image D., below, I made a mistake which I think is worth highlighting – I placed seeds on both the top and bottom halves of the paper towel and just starting rolling it up. Because the paper towel was not first folded (as in image C.), seeds stuck to the outer layer of the paper towel when it was unrolled - This made later counting much, much more difficult as seeds were stuck to either side of the paper towel.

After Image C., The next step is to make roughly 1.5-inch folds/rolls in the paper towel until you have something like what is seen in image E. For organizational purposes, I combined multiple germination tests (for different plants) and placed a rubber band around them (image F.). To prevent drying out, your germination test(s) should be placed in a plastic bag of some sort.

Tip: The paper towels should be damp but not dripping wet.

Step 4: Results & Analysis

By day 3 some seeds in my tests had already begun to germinate; the number of germinated seeds should be counted and recorded. 

Tip: It may be necessary to periodically rewet the paper towels.

But, as it goes, a few problems were encountered....

Image K.: Some seeds became fuzzy with fungi; this can largely be prevented through additional aseptic steps (discussed below). 

Image L.: It can also be easy to convince oneself, as I did, that seeds are germinating when actually they are not. Coriander / cilantro seeds are tricky, in my opinion; when I stared at them long enough, I began to see that they had germinated! I snapped a photo and compared it with the same seeds a few days later, and also found some un-tested coriander seeds to compare against... no germination had actually occurred.

Image N.: Unfortunately, a major blunder occurred during my eagerness to cleanup. Days after starting the test, I realized that I had tossed out the seed packet for the corn cultivar which I was testing! I highly recommend holding on to those, as well as making good reference notes!

Tip & Note to Self: It can be very helpful to keep seed labels and few reference seeds around!

Step 5: Calculation

The final step is to calculate your results! After 7 – 10 days, divide the number of germinated seeds by the total number of seeds in your trial.

In my tests, the pepper seeds did not respond very well and demonstrated a 45% total germination rate. I believe that this was most likely due to issues regarding temperature.

Temperature & Germination Time:

Knowing the difference between Warm and Cool season crops, as well as the general number of days until seed germination, can be incredibly helpful – A wonderful cheat sheet can found in Table 1 (pg. 3) of the following CSU – Colorado Master GardenerGuide.

Peppers, for example, prefer a soil temperature of 80°F and are notorious for taking a long time to germinate (an expected 10-20 days). Watermelons have similar temperature requirements to peppers but are expected to germinate somewhere between 3-12 days.

Tip: A seed propagation or heating mat can greatly improve the germination rate of seeds.

Aseptic Technique:

Implementing additional aseptic or seed disinfesting techniques can reduce the likelihood of contaminated seeds (Image K, above); if contamination is a problem or concern, the following publication from LSU Extension & AgCenter may be of interest.

Replication:
Repeating a ‘trial’ or single germination test two additional times (with each test occurring on a different day) would add to the robustness of a test’s final results. This means re-doing the 7-10 day trial, three times independently and weighing your overall results... But everything is a balance. Some seeds should be saved for planting in the soil!

So What? The value of knowing seed viability

Knowing the germination potential of a seed cache allows one to plan accordingly. If seeds present a 0% germination rate it may be due to a faulty test, in which case it can useful to re-test the seeds or look into temperature requirements or other confounding factors. If the seeds present a 90% germination rate, AWESOME! - One can be fairly confident that planted seeds will germinate successfully; whereas with a 0% - 50% germination rate, it may be necessary to plant seeds more densely or to check over one's seed storage conditions.

Good Luck & Happy Gardening! 

Avoiding Abiotic Afflictions …in the spring garden

Posted by: Mary Small, Jefferson County Extension Plant Diagnostic Clinic

Abiotic plant problems are brought on by environmental or cultural conditions. They often mimic disease, but are not caused by any living organism. They plague many gardens and landscapes, even, unfortunately, at the very beginning of the growing season.

Planting seeds is a favorite springtime rite. Once in the soil, they’re watered and watched for what seems like an interminable amount of time. And then….nothing…or spotty germination. More time goes by…hmmm….what’s a gardener to do?

Check the age of the seed.  All seeds don’t remain viable for the same amount of time. For example, corn stays viable for around two years, yet tomato seed is viable for five years. If you are using older seed, you may first want to conduct a “rag doll” test. Take 10 seeds, place down the middle of a paper towel, roll it up and fold the sides under, so seeds don’t drop out. Moisten the paper towel and place in a sealed plastic bag on the kitchen counter. Once the time to germinate has elapsed (found  on the bag of seed), open everything up and see how many seeds have germinated. If 7 out of 10 did, then you have 70% germination. You may want to sow seeds a little thicker to make up for the reduced germination rate.

"Rag doll" test for seed germination

Some seeds produce weak seedlings and may need some help emerging through the soil especially if it crusts over easily.  Carrots are a good  example of this. This year, try planting the seeds as usual, then cover the row with a piece of burlap or a board. This helps prevent soil crusting and allows the tender seedlings to germinate. When it gets close to the expected germination date, lift the covering and start checking the progress. Once most of the seedlings are up, you can remove the covering.

Weak seedlings are the reason radishes are often interplanted with carrots.  The stronger radish seedlings germinate first, making way for the carrots. They’re harvested in about 30 days and create even more room for the developing carrot roots, although thinning may still be needed.

Carrot seedlings planted with burlap
(from tinyfarmblog.com)

Beans sometimes have germination problems.  If placed in soil that’s too cool, they don’t sprout and  may rot. Even when beans germinate, I often get questions about how to control  “the birds ( squirrels, rabbits or any other critter observed near the garden) that are eating the leaves off the bean plants”. This problem is not caused by animals. It’s called “baldheading” and is caused by mechanical injury to the growing point of the seedling. Crusty soils and damaged seeds are the likely culprits here.

"Baldheading" of beans caused by mechanical injury to seedlings

Sweet corn planted in too cool soil, like beans, does not germinate (or germinate well) and may rot. Supersweet varieties actually need soil temperatures of at least 60 degrees F to germinate.

To check soil temperature, insert a soil thermometer several inches deep into the soil. The soil must be the desired temperature for several days before planting.