Most people have a problem with the time part of gardening although with proper planning the money part is not, necessesarily, a part of the problem.
Look around and think about the resources you have readily available, food waste is one, and free that you can utilize. Look at the soil you have to see what needs to be done with it. These simple soil tests can help you determine some of that,

1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains� too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.
Talk with the people at the local office of your Washington State University Cooperative Extension Service about having a good, reliable soil test done. Take some time to look into the concept of Lasagna Gardening.
There should not be any reason to spend a lot of money to get your soil into a good, healthy condition that will grow strong and healthy plants.

Here is a link that might be useful: Lasagna Gardening 101

First of all, I'd like to point out that raised beds are not a requirement for gardening. I've always gardened right in the ground, and I continue to do so. That being said, however, one of the most often cited reasons for gardening in raised beds is that they drain well, so I wouldn't worry about having the opposite problem if you do go that route.

You'll want your soil to be able to retain moisture without getting soggy. What is your soil like now? When you look at the area where you intend to put your garden, does it dry out quickly in the Spring (or after a heavy rain), or is it muddy for a long time?

Working organic matter into the soil is bound to help, pretty much no matter what, and with a little bit of looking around, there are often many free sources that can be found.

Raised beds offer several advantages over gardening inground. They offer improved drainage, the soil heats up faster in spring and cools down slower in fall (extends the growing season) and because one usually brings in soil to fill raised beds, you can manipulate the soil to provide the optimum conditions.

Seattle soils are very slow to dry out in spring as well as slow to warm up adequately to encourage either seed germination or the growth of veggie starts. Raised beds are an excellent alternative to this.

btw, peppers, eggplants, tomatoes and other warm season crops tend not do as well here as the cool season veggies (peas, beans, onions and other root veg and greens). It seldom gets warm enough here in summer to encourage a lot of flowering or fruiting and good ripening is typically limited to those that have a short harvest period. These need the sunniest possible location with the warmest soils to do well. Raised beds often offer better results with these types of veggies because the soil will be warmer, but many local gardeners choose to grow them in containers as these provide even more suitable soil conditions and can be moved to maximize sun and reflected heat.

> soil heats up faster in spring and cools down slower in fall

I keep reading statements like this about raised beds and it sounds contradictory to me. I just figure if it heats up faster in the day, then it cools down faster at night. And if it heats up faster in spring then it cools down faster in the fall. Thermal inertia works both ways. Am I wrong here?

tcstoehr,

Raised beds likely have more organic matter in them due to the extra care they have received. More organic matter translates to more bacterial and fungi action which translates to more heat in the soil...even in falltime.

This is my take on it. If a soil has all the good qualities in it including optimum trace minerals, the plants themselves are more resistant to frost damage even.

And if it heats up faster in spring then it cools down faster in the fall.

Well, not necessarily. If, for instance, the sun helps the bed warm up, then the sun will help it warm up in both Spring and Fall. I'd wonder about what impact that has in the hottest part of the Summer, though.

I just figure if it heats up faster in the day, then it cools down faster at night.

I'd have to guess that it depends to some extent on the specifics of what your bed is built from, and its dimensions. It's possible that dirt, being mostly dark in color, absorbs heat from sunlight at a greater rate than it radiates it out in darkness.

I do have one raised bed (built for decorative purposes, rather than any sort of gardening advantage). It's built up against a concrete retaining wall, and the sides are built from those "Windsor" wall stones. As I look out my window now, I see the snow on this bed receding, while the in-ground bed is still covered with quite a bit of snow. I'm pretty sure that once the sun managed to find a small corner of the stone, the stones just sucked up heat all day and held onto it.

All of that being said, however, I still worry about new gardeners thinking that they "can't" garden unless the first thing they do is build a raised bed and buy some stuff to fill it with. It simply isn't so. Then again, I'm a New Englander, and our soil is over all quite excellent to start with, and the drainage in my own yard is just fine. I wouldn't want to cover over my wonderful soil with something I trucked in.

I'd generally encourage a new gardener to get started in smaller ways, and get a little bit of success under their belt, before putting huge amounts of energy into optimizing things. Then again, as I mentioned, I live in an area where you really can get a fair bit of "success" with little more than turning over some soil and putting in some plants.

Yes, I gardened for decades without raised beds and such. If you do raise a bed and have good soil to start with, like me, you can mix it all together deeply and have an excellent bed.

I'm gonna have to disagree with your #5, kimmsr. I rarely see worms when I dig in my soil, but my plants are all healthy. They produce large, flavorful crops and I only see worms after a rain or after watering.

The presence of worms is a good indicator of the quality of your soil, but you don't have to see them to know you have a healthy soil.

leira - I'm absolutely with you on this. For a beginner it can be daunting thinking you have to have raised beds, imported soil, amendements and all the rest of it. If you have reasonable native soil you can just start with that. I have grown perfectly fine vegetables for many years just on the earth I have with the addition of my own compost and occasional loads of manure.

p.s. I also have way fewer than 5 worms per shovel. The veggies don't seem to know they are growing in unhealthy soil.

I just figure if it heats up faster in the day, then it cools down faster at night. And if it heats up faster in spring then it cools down faster in the fall.

It's not quite that simple :-) There is a rather complex relationship between improved drainage/moisture retention, increased porosity, gas exchange and solar radiation. Wet, compacted soils are slower to warm in spring and faster to cool down in fall. Very well aerated soils - such as those typically found in raised beds - respond to solar radiation more rapidly and because of their increased exposure (i.e., sides), absorb more during daylight hours and are slower to release it at night.

Even in very cold winter areas, a well-aerated, well-drained, loose soil in a raised bed may not freeze solid whereas the inground soil will.

In the Seattle area - which I am most familiar with - raised beds offer advantages to the veggie gardener that may be not be as apparent elsewhere. First, we DO have cold, wet winter soils and soil temperatures affect crop growth more than most other factors. If one has to wait for inground soil to dry out and warm up properly for the growth of young veggie starts, you are shortening your gardening season by a good month than if you planted in raised bed soil. Second, we DO have heavy, clay soils (by and large), natural drainage is often poor and the looser and more organically fertile soils common to raised beds just affords much better drainage than planting in the ground. Finally, PNW soils tend to be acidic, sometimes significantly so. The soil in a raised bed is far easier modified to an appropriate pH (and will remain there better) than inground soil.

For new gardeners, I think it is helpful if they start out with as positive a first time experience as possible and in the PNW - unless you already have well-amended, fast draining soil - raised beds will overcome a lot of unnecessary hurdles.

You may want to look into square foot gardening it gave my sister a very positive first year and was cost effective and pretty easy to maintain

I think the raised beds warming up sooner - which they surely do - has a lot to do with there being more air in them. Which is why they will have more drought problems in summer. In light soils raised beds are hardly if at all helpful. Light soils if exposed to a dark surface warm up quite fast. Keeping the profiles flat or even concave helps reduce drought when the hot wether comes.

"hot" weather in Seattle is relative :-) Summers here tend to be very cool compared to other parts of the country, if somewhat dry. If one uses a soaker hose in a raised bed, sufficient irrigation is seldom an issue even in the warmest, driest periods.

Completely agree with gardengal. Gardening in PNW is different from gardening in other parts of country.
Raised beds, high tunnels, containers and greenhouses are helping here more if gardener wants to grow heat loving veggies.
I could not imagine gardening in Seattle area without raised beds.

I completely agree PNW vegetable gardening is quite different and has its own set of challenges. That's why alot of gardening books are next to useless for this climate. I just don't buy the notion that raised beds average out to be any warmer during our Spring or Fall weather.
Pnbrown - I agree that an airy mixture will heat up faster due to it's reduced thermal inertia, but that will also cool faster as well.
Gardengal -
It is logical to figure that the increased exposure of a raised bed during warm periods will increase temperatures within that bed faster than an in-ground situation. It is also logical to figure that cold periods will cool the bed faster than the ground. But just because it sounds logical doesn't mean it's true, but I'll have to have some reasoning as to why it is not so. Perhaps the answer lies in the fact that during the bulk of the gardening season the day length exceeds that of the night length. I had not considered that factor.
Maybe I'm spoiled from having a natural sandy loam soil that drains well and is easily worked early in the year.

Another (ex-) Washingtonian who sez raised beds and low tunnels-coldframes are helpful. Anything to create heat!

One thing about raised beds is they dry out faster in addition to heating up faster. And mine here in Colo don't freeze like the ground does (because the sun warms them up).

Dan

Dan, it depends where you live. Maybe I'm lucky but I have absolutely no need for increased drainage. Tunnels over my beds however would be sweet! I just can't get myself to invest the materials, money and work into it. Although my coldframe is stuffed to the gills every year.
As far as raised beds being warmer in the Spring and Fall, I'm just going to have to agree to disagree with y'all. I'm just not seeing it. But I'll keep my eyes peeled.

You are certainly free to disagree - that is your prerogative - but it is not just us that you are disagreeing with. Virtually any literature you will find on raised bed gardening will state the same thing. Raised bed soils heat up faster in spring and can retain more heat in fall and even absorb more solar radiation in winter, effectively extending the growing season.

Extended season. Raised beds heat up earlier in the spring. Because of their height, they intercept more of the sun's rays in late winter and early spring. This phenomenon permits earlier seeding and transplanting. Plants also grow faster once they are established. Samuel Roberts Nobel Foundation, Agricultural Research

Raised beds eliminate soil compaction. They heat up faster in the spring and stay warmer in the fall, adding as many as three weeks to your growing season. The Instant Organic Gardener

Raised beds have better soil structure and drainage, allowing the soil to warm up earlier in the season, and giving you a head start on spring. U of Minn Extension

Raised-bed gardening can increase soil temperatures by eight to thirteen degrees over ground level soil temperatures. The soil is more exposed and the sun and wind tend to dry and warm the soil quickly. Raised Bed Vegetable Gardening for Cool Climates

And these are just a very few of dozens of similar comments. Just Google "raised bed soil temperatures" and see for yourself.

GardenGal - this is the sort of thing that I'm not going to believe or disbelieve just for having seen it on the internet. So much gardening conventional wisdom is pure nonsense, not that this is, I simply don't know. Many things get common acceptance for having been repeated over and over with no proof. Additionally, there's a ton of confirmation bias among people's gardening preferences. When Ed Hume claims an 8-13 degree difference because the sun shines on one side of a wooden raised bed, I'm totally skeptical. Further, if none of these people address the night time temperature influences of the raised bed, then it's largely meaningless. If the increased area exposed to warm air and sunshine during the day raises temps, then that same exposure during the night time will accelerate cooling by radiant heat loss from the increased exposed area. Nobody addresses that aspect of this, yet plants grow at night too. Why does nobody talk about this? Simple... they're trying to tell you the advantages of the raised bed and they will simply ignore the flip side. They'll tell you that raised beds store heat for the night time, but they won't say that they store cold for the day time just as easily.

Having thought about this a considerable amount and not being totally convinced one way or the way, and remaining extremely curious, I will conduct an experiment this season. I'll construct a 4' square 12" high raised bed similar to the ones Ed Hume says are 8-13 degrees warmer:

Ed's Beds

I will measure the temperatures using both of my soil thermometers each morning and late afternoon and daytime when I can. I'll plot those temperatures along with temperatures taken at the same time from my non-raised beds. March 21st - Oct 21st. I'll post the results on this forum for the curious.

Can I use my native soil for the raised bed, or does it have to be a pure organic mixture? How 'bout half and half?

Ah, well GGal. A for effort!

Dan

Dan... that's because the horse knows best when to drink and when not to, even when told otherwise.

LOL!! You're right, Dan -- I give up :-)) Forget that agricultural research stations and university extension services document this phenomenon......Ed Hume must have just pulled those temperature differentials out of thin air!! And the rest of us just parrot it back despite our own experience.

tcstoehr, do yourself a favor and get a copy of Environmental Soil Physics by Daniel Hillel and read Chapter 12 - Soil Temperature and Heat Flow. But put your scientist's cap on cuz it's kinda heavy, which is why I didn't get into the science of it any deeper than I did. The whole forum would be asleep by now.......:-)

> Forget that agricultural research stations and
> university extension services document this phenomenon.

I didn't see any actual documentation, just alot of folks repeating it. If you could point to actual studies doing this, I'd like to see that data. It would save me the time and effort of doing it myself. That would help me out a great deal. I mean... where is this data? I may well have missed it but I want to see the trials where they actually stuck the temperature probes into the ground, recorded and analyzed the data.

Do I think Ed Hume just pulled those numbers out of thin air? I've met and talked with Ed a couple of times after listening to his lectures, and I wouldn't put it past him. But I think he, like alot of folks, may just be accepting and parroting conventional wisdom like most of us do. Happens all the time. I certainly don't put everything I read to an actual test. I accept alot on faith and common sense. This particular case fails my common sense test. And I haven't seen anything to convince me that daytime temp gains in raised beds that persist into the night are not offset by night temp losses that persist into the day.

"Environmental Soil Physics" is a bit pricey to say the least. I think it will be cheaper and alot more definitive if I actually perform the appropriate experiment myself. Plus I'll have a new raised bed to plant in when I'm finished. It will be interesting to see the effects as we move from early Spring, thru the Summer, and into Fall. See you then.

Not all raised beds are bordered...none of mine are wooden sided which might block some sun rays on the edge. Concrete and stone edging can carry heat into the night though.

Some farmers do some fall ridge tilling to help the soil warm and dry out sooner in the spring. Dryer soil warms up faster than wet soil....the water conducts heat downward into the deeper soil.....and likely upward into the atmosphere. Heat moves to cold. Heat is a measurable substance while cold is only a lack of heat.

I agree with tcs that a lot of different factors are getting lumped together here.

Raising soil up in a mound will cause it to behave differently than what is around it. Soil of a dark color bared to the sun will cause it to warm more than soil around it that is covered with something lighter-colored, regardless of day and night temp variation. And VERY obviously plastic or glass coverings make a very big difference. All those things are unrelated. A raised bed isn't necessarily a bare bed, or a bed with a cold-frame or tunnel over it. A raised bed with a foot of hay or snow on top of it isn't going to warm up hardly at all faster than flat ground with a foot of hay or snow on it, for example, in part because the hay or snow is probably covering the sides as well as the top. Part of why a raised bed often warms sooner (in addition to being dark on top, perhaps, and maybe having a frame on it) is that the stored cold of the whole winter that is in the top 4 or 5 feet of earth is slowly spilling out the sides of the bed. That is what is happening in a ridged field - in addition to the exposed dark soil gathering heat from the sun during the day, at night in early spring the air temp is likely a little higher than the average ground temp and so it is sucking the cold out from areas that have increased bare exposure faster.

I agree pn, but then the entire...erm..."reasoning" is blown with the erroneous conclusion [n]obody addresses that aspect of this, yet plants grow at night too. Why does nobody talk about this? Simple... they're trying to tell you the advantages of the raised bed and they will simply ignore the flip side.

This is why GG mentioned the soil physics book. It is the easiest thing to comprehend that someone needs some of that there physics learnin'. Heat capacity. Heat capacity is why raised beds work. Heat capacity is why you water your soil before a frost comes.

So folks who are wondering if raised beds are better, yes.

They are better because of:

o the solar gain afforded by the increased aspect of the sides, and the heat capacity therein.
o They also can have looser and amended soil, etc.

But the topic is heat and the subsequent topic is why. The original question was moisture retention, and because of the increased solar gain and exposure to free air, raised beds dry out faster, but mulch helps. The downside of raised beds is the cost to construct them and you have to replenish the soil in them (compost helps here).

This is basic knowledge. The cost is usually what prevents folks from doing them, but once you get it down, you never go back.

Best regards, pn,

Dan

tcstoehr, I admire your initiative in wanting to research this......nothing wrong in wanting to confirm what one reads in passing :-) However, I doubt there are any 'scientific' studies that have been done to confirm this phenomenon, at least none that I could find. It's not like there is any difficulty in doing just what you propose - measuring the soil temp in raised beds and comparing that to inground soil temps at various times throughout the season. This is not rocket science and such an activity hardly needs a documented "study" to verify and I'm sure various sources have followed exactly that process to support their claims.

I guess it's a matter of priorities, but most of us are willing to accept that this is a true phenomenon without the need to go through the process of actually measuring and evaluating the temperature differentials - the effect is pretty darn obvious if one has done much raised bed gardening!

But if you want to understand the science behind the results, then the Soil Physics text will provide you with all the details. It is just not a very layperson-friendly presentation:-)

This one is pretty good for beginners. Singer was my soil prof in undergrad and excellent teacher. My text (4th Ed.) explains the conundrum in question in Ch 4.

Dan

In rereading my explanation about heat, I can see that I partly failed.

Raised soil can warm up faster IF it is dryer. Soil lying flat and wet is slow to warm up because water warms up slower than land. The large body of water is slower to warm up and slower to cool off in the fall than the land mass...make any sense?

It just about has to be drier, doesn't it, if it's raised? That's why ridging sandy soil can backfire in hot weather. Hence one learns pretty quickly not to ridge. I generally do the opposite - plant in hollow furrows so as to hold as much water as possible.

It just about has to be drier, doesn't it, if it's raised?

Chances are excellent. Almost imperative to mulch in raised beds. BTW - planting in the furrows is a trick in arid and semi-arid areas. You're on to something!

Dan

> Raised soil can warm up faster IF it is dryer.
> Soil lying flat and wet is slow to warm up because water
> warms up slower than land. The large body of water is
> slower to warm up and slower to cool off in the fall than
> the land mass...make any sense?

Yes, that makes complete sense. I'll work with your analogy comparing a raised bed with a land mass and the flat soil as an ocean. The land mass warms up more than the ocean in spring... during the day. At night the land mass gets colder than the ocean, often freezing. The warm soil at the end of the day persists for some time into the night, and the frozen soil in the morning persists for some time into the day.
It all works out in the wash, it seems to me. Change the thermal inertia and you will gain on one end and lose on the other. Increase the lateral exposure to sunlight by raising the bed and you will gain from incoming solar radiation during the day but you will lose from increased radiant heat loss during the night.
Perhaps the whole point is that warm daytime temperatures are desirable even if the night temperatures are lower. I've been arguing the point that the *average* soil temperature is not going to change much. I figured plant growth happens as much during the night as during the day, so low night temperatures would offset higher temperatures during the day. Maybe that's a fallacy.

Maybe that's a fallacy.

Yup. Especially the incorrect point about lower nighttime temps, therefore the repeated observations about physics.

Raised beds improve growing conditions and allow for much more flexibility, especially up there.

Dan

tcs -- This will be an interesting experiment. Having steel-sided raised beds in Portland I'll be interested to see what you find. Folks have opined that our beds do so well in part because they heat up quickly in the sun, but I've never measured the effect. I have a few thoughts about your testing...

An important variable will be the depth of the measurement - ideally at least 4-6 inches to replicate the root zone - within a conventional bed about 16-18 inches tall. The depth matters to somewhat isolate the effect of the bed walls from the top surface heating - which the non-bed soil would also experience.

There should be equal amounts of water applied to the bed and non-bed test sites so that soil water content isn't too diverse a variable. I think the soil in and out of the bed should be the same to eliminate the soil and saturation variables.

Another interesting factor would be measurements of temperature at several distances from the walls of the beds, and the directions the walls are facing. South-facing walls ought to get the most radiant sun heating, while cooling ought to be uniform on all sides.

Another factor would be the material and thickness of the walls. The included link shows that wood (pine/oak) has a similar thermal conductivity to soil with organic matter. Saturated soil has a higher conductivity, with comparable to concrete, or much higher (depending I suppose on water content for saturation). A wood-sided bed and a brick/concreted sided bed would be an interesting comparison. (The thermal conductivity of our steel beds is about 300x that of wood...)

This will be interesting. Looking forward to what you find.

Here is a link that might be useful: Thermal Conductivities

pdxmark - I was planning on using 2 x 12 untreated fir, like the ones in the link. I suppose a bit higher would be better. You raise a good point about the soil makeup. Alot of folks consider a "raised bed" to be full some sort of an organic blend. Lighter, airier, quicker draining, less thermal inertia than even most amended soils. When people say "raised bed" the artificial soil content is often implied. I was thinking 1/4 each of native sandy loam, peat moss, compost and some cheap bagged organo-blend. I'm looking forward to it.

mendozer - I agree with the earlier post, concentrate on growing the easy crops first. You can learn the finer details and build up over time. The easiest crops in the spring are turnip, thumbalina carrot, detroit dark red beet, peas, okra, chicory, green beans, and onions. In the fall, plant kale, collards, and leek. These are tough as nails so it is hard to go wrong.

Here is a link that might be useful: GardenForNutrtion

I doubt there is enough heat there to grow okra, but the rest of the list is a good starting point.

Dan

I'll just add to Dan's comments about okra and heat......hot season veggie crops in the Seattle area are always problematic - tomatoes, peppers, eggplants, okra, corn, etc. It is very tough to get these to a successful harvest in our very cool summers. These virtually require a raised bed/warmer soil temperatures or be grown in containers that will also heat up sufficiently and have the advantage of being moved to maximize sun and benefit from any reflected heat.

To the OP - if you are still around - pick up a copy of the Northwest Maritime Garden Guide at any local book store or retail nursery. This is the bible for veggie growers in our area, newbie or not - and will provide you loads of info on how and when to grow to veg in our unique area and the best varieties to consider. Cool weather crops will flourish.....others can pose difficulties.