Have you ever eagerly planted seeds, but your results were less than stellar? Nothing came up? New starts died? Young plants were straggly and weak? Don’t dismiss your efforts as having a brown thumb — use these tips for understanding seed packets to ensure sowing success!
By the time late winter rolls around every year I get the itch.
The seed starting itch.
And let me tell you — that is one itch that needs to be scratched.
If you are a plant lover like me, you find yourself in a similar situation year after year. Successfully starting seeds is a tremendous cost saving measure, especially if your garden or your ambitions are expansive. Spending a couple dollars on a seed packet of heirloom tomatoes or sunny, healing calendula can potentially produce dozens of plants, whereas spending the same money on plants will likely only get you a solitary specimen.
So why isn’t everybody starting their own seeds?
Well, because the failure rate when you are first starting seeds can be quite disheartening.
But it doesn’t have to be.
Understanding the information on the back of your seed packets is the key to seed starting success!
While I am by no means an expert on seed starting, here are a few of the tips and tricks that I learned from the back of seed packets:
Understanding Seeds Packets 101
Direct Sow or Start Indoors
This is probably the most important information to heed on your seed packets — whether to direct sow (i.e. planting seeds outside, directly in the ground where they will remain) or start indoors (perhaps in a sunny windsill, under grow lights or in a greenhouse to be transplanted later). While some seeds aren’t picky, appearing to thrive equally whether pampered or left in the elements, other seeds are far more particular. Certain seeds perform better in a controlled, mild environment and tend to tolerate transplanting well. Still yet, other seeds will only come up after surviving relatively harsh conditions outdoors and abhor transplant. For the healthiest plants refer to your seed packet to point you in the right direction here.
The germination rate indicated on a seed packet suggests the average time it takes from planting seeds before tender new growth emerges. While some seeds are early risers, others can take weeks or more before peaking out of the soil. When planting seeds in larger trays with other seeds, be sure to choose seeds with similar germination rate so you don’t find yourself with giants and peewees stuck in the same tray.
This term refers to the approximate percentage of seeds that are expected to germinate successfully. Some germination rates can increased by the various seed preparation strategies a few headings below.
Timing/Date of Last Frost
Another really vital piece of information on seed packets essentially tells us when to plant our seeds. Most seeds packets will give you are range of weeks before “the last frost” for your area. Minding these suggestion will help you to have healthy seedlings at the right maturity for transplant if started indoors, or will help to expose your seeds to the proper climatic conditions that it needs to germinate if planted outdoors. Not sure of your expected date of last frost? Call your county extension office or a local Master Gardener’s Chapter to get last frost information for your area.
While some seeds are more drought tolerant than others, and still others love swampy, boggy conditions, most seeds require damp soil in order to germinate. Generally speaking, the soil should be evenly moist, basically holding shape if clumped in your palm. This is easily achieved by pre-moistening your starting mix before packing into trays or pots. You’ll want to maintain this level of moisture while the seeds are germinating and in the first weeks as the seedling develop. Do not let your starting mix dry out; also, do not over water. I use a spray bottle or add water to “self watering trays” when dry.
Special Seed Preparation
To be honest, this little section right here was my primary reason behind this post — too many seed failures are due to poor seed preparation. A great many seeds require little else other than soil, water and light to germinate, but others necessitate a bit more work. Below are some preparation methods you may encounter on your seed packet:
- Scarification: It took me a while before I built up the confidence to scarify seeds. This method is often used with relatively substantial seeds with a robust outer coating. I use a pair of dedicated nail clippers to nick the outer coating just enough to reveal a small amount of inner seed material before planting seeds like sweet peas and nasturtiums.
- Soaking: This method is rather simple and self explanatory. Soaking seeds prior to sowing will soften the out layer seed layer, helping to ensure germination. Follow the advice on your seed packet for duration of the soaking time.
- Stratification: Some seeds require a period of persistent cold before they will break dormancy and sprout. I prefer to use the paper towel method in which seeds that have been soaked for a short amount of time are placed between a couple sheets of damp paper towels then sealed in a plastic sandwich or storage bag and refrigerated for a period of time (your seed packet should recommend the duration of if stratification is in order).
Please note, that these seed preparation methods should help to increase germination rates, but seeds may come up without it. I am mindful of preparation suggestions because there is little more disappointing than seeds that germinate so late in the season that you are not able to enjoy the plants in their maturity.
While seeds themselves mostly just need warmth, water and soil, seedling need LIGHT — and, generally speaking, a LOT of it. When starting seeds indoors, it is vital to figure out the your lighting situation. While a sunny window will certainly produce results, brighter light — such as that emitted by grow lights positioned directly above the seed trays or the bright. diffuse light observed in a greenhouse will result in sturdier, stronger seedling. If your seed packet does not indicate specific light needs, I suggest erring on the side of too much over too little, and always rotate your seed trays if the lighting situation is uneven.
Soil Temperature Requirements
Heed the advice of your seed packet when it indicates the seed’s soil temperature requirements — especially when planting outdoors. Some seeds require a certain about of cold days, while others prefer to be tucked into the soil. If your seed packet suggests a temperature range, it is advisable to probe your soil with a thermometer like this.
Be very mindful when a seed packet suggest a seed planting depth. Some seeds want nothing more than to be gently pressed in to the surface of the the soil, while other prefer to be planted more deeply. If your seed packet does not indicate such, I generally plant more substantial, robust seeds 1/8″-1/2+” below the soil surface (a good rule of thumb is to plant seeds roughly twice as deep as their diameter, and more whisp-y seeds simply pressed into the soil surface.
Days to Maturity
Days to maturity refers expected about of time from the date planted to maturity (flowering or fruiting depending on the particular plant). This is particularly important information if you have a short growing season. Select seed varieties based on the “days to maturity” on your seed packet to help ensure you will realize the full growth cycle of your plant.
Not every seed packet will indicate growing zones (especially if they are annual), but do pay attention to growing zones when planting perennials, biennials, or free seeding annuals to ensure that your chosen plant is hardy in your growing zone. US readers -you can find your growing zone here.
Spacing or Seed Density
I hear Monty Don say that there was no virtue in over sowing on a recent episode of Gardener’s World – and frankly, he words burned in my cheeks. I am 100% guilty of over sowing, planting too many seeds to a cell, and generally being too liberal in my seed scattering. If your seed packet suggests how densely to plant your seeds or how far to place them apart — this is excellent information and you really ought to pay attention to it. Too many plants leads to competition for light, water and nutrient resources.
In the same vein as spacing and seed density suggestions, thinning your seedlings is a painful aspect of starting seeds. Inevitably, the time will come to reduce the seedlings per cell or the starts in a row, selecting for the strongest among the baby plants. This seemingly harsh act of garden malice is actually an act of mercy for the garden. Selecting the fittest among the seedlings will help produce stronger plants and more prolific crops. Anybody that has pulled up puny carrots months after sowing knows what I am talking about. Thin your seedling according to seed packet directions and you will be rewarded.