Allow me to present - ta daah - the Desperation Germination Technique! Invented to test which parts of an ageing seed collection were still viable, its method is very simple: take small, shallow, see-through plastic containers, fill with lukewarm water, put seeds in, put lid on or cover with plastic, and leave in warm place for a few days. The water will prevent the seeds drying out (duh) and act as a temperature buffer by absorbing extremes of heat & cold (but should always be kept lukewarm) and also keep the submerged seeds from getting mouldy. For seeds with germination inhibitors in the seed coats, change water every day; for seeds with waterproof seed coats, chip the seed. If nothing happens even after a week, or if the seed rots, either the seed is dead or this type of seed doesn't lend itself to underwater germination. If it does germinate, wangle the delicate sprout (often too delicate to be held between the fingers) onto a teaspoon and drop into a pot of pre-moistened cocopeat or other sowing mix, and cover lightly.
What makes this method preferable to the usual "let's sow everyting in a tray and see what comes up": i. the containers are easier to clean than seed trays; ii. all seeds that do end up being sown have already germinated, so there's no damping off due to non-viable seeds rotting away in the same soil as the viable ones; and iii. because the seed has already soaked up enough water to germinate, the soil it is planted in doesn't have to be kept so wet, and there is less chance of rot, especially with big-seeded plants like cucurbits. The seed should preferably be fished out and planted as soon as it sprouts, but tomatoes are so unfazed by this technique that seedlings left to soak for days have completely burst out of their seedcoat under water, putting out shoot and root, unfolding their leaves and growing in curlicues because of the light shining on them from all directions; after planting, these tiny spindly seedlings became healthy plants.
This method doesn't work for teeny tiny seeds, or seeds that need stratification, or seeds with lots of fluff around them that can rot and dirty the water. It does work with clean round seeds that germinate in the rain season anyway, like cactus seeds, and with all solanums, especially tomato seeds that have not been cleaned through the fermentation process and therefore need to get that dried-up coat of gel soaked off. Cucurbit and sunflower seeds like this method too, but should be removed after they are swollen, but before they start to sprout. Peas, beans and their relatives love to germinate in water, but are best soaked until swollen and then planted in soil while they are firm, as at the seedling stage they are much more fragile. Corn kernels love water too, and since they are short-lived, it's a good way of separating viable kernels from the already dead ones. Individual species that this method worked for are Lippia dulcis, Zaluzianskia capensis, Ionopsidium acaule, and Diospyros virginiana; it doesn't work so well with Salvia and basil seeds since these have their own special coating to keep them moist. All I can say is, if you're desperate, try it!
A second germination technique is to mix seeds, preferably in something moisture-retaining like perlite or vermiculite (but perlite does dry out and vermiculite sticks to your fingers) or in soil on top of capillary matting; anything to make sure the seeds, while not drowning, will never lack water. I discovered this when sowing the famous "lottery mix" (last year's seed mixed together, for people who like surprises) from Chiltern Seeds. I'd sown a packet of Tellima grandiflora, and literally nothing came up. And from the lottery mix with all sorts of seeds mixed together, one of the plants was Tellima grandiflora. I've similarly had other plants from mixed packets that would not come up in "monoculture" sowing. Apparently different seeds in the same soil somehow encourage each other. (Note: there are seeds, like sunflower seeds, that inhibit germination in others.)
Seed-selling sites will typically have an information page on how to germinate their seeds. Interesting pages on germination are:
Pages about tomatoes:
Pages of general interest:
Ludicrous short tips:
A barrier of sawdust spread around a bed (under a cover if in a rainy climate, to keep it dry) will repel slugs, but cats will think: "Eeeee! Kitty litter!" and there goes the barrier.
Cats can be discouraged by clippings of thorny branches, like those of Rubus phoeniculasus. Be careful how you put such branches on sawdust slug barriers: slugs may use them as bridges.
Copper tape, which I buy from the Dutch site Kopersporen, also deters slugs and snails, but the copper seems to erode away very quickly. Their equally effective rings of solid copper are much more durable. (Sadly the surface of the rings also rapidly forms a corroded layer that slugs laughingly slide over; I'll have to find a copper polishing product.)
For dog owners and people who remember the days before every camping site had toilets, and campers had to use a "pee bucket": diluted urine makes excellent fertilizer, especially for indoor plants. It only starts to smell if left standing; fresh, it's practically odourless.
Depending on what bedding is used (newspapers no, sawdust and straw yes) soiled bedding from small pet cages (hamsters, rabbits) makes a good addition to the compost heap. (Note that sawdust is bad for pets' lungs; there is a dust-free alternative made of hemp.)
For Passiflora seeds and other seeds that have to be soaked overnight in something acid: the standard solution is sour milk, and I'd use other acid milk products, like yoghurt that had been in the fridge too long. But for those who have impaired digestion and drink concentrated whey for their protein intake: concentrated whey is just as good, doesn't smell, and is transparent enough (unlike milk or, worse, yoghurt) to still see where the seeds are.
A good soilless seed-sowing mix is cocopeat (in Europe, replacement for peat which has been harvested to the point of exhaustion) with sand. Recommended is builder's sand which has to be washed first. I have a better recommendation: bird cage sand. I use a brand called "Javame" which comes in 5 kilo bags. It has little chips in it for the birds to swallow and aid digestion, which don't hurt me when I'm mixing it with cocopeat (nevermind the peat:sand ratio, I just keep mixing until it looks good) and it has been treated with aniseed to keep the cage cleaner; I don't know if this also helps against damping off, but it smells nice.
Despite being sun-lovers, salvias are remarkably shade-tolerant. Some common
sage (Salvia officinalis) plants managed, despite their grey leaves, to survive
for years in the deep shade of a plum tree. In even deeper shade lived a plant
that I'm sure was Salvia uliginosa. Some Salvia coccineas lived long and
flowered on a windowsill, despite being covered in aphids as a gentle hint that
they were not truly happy there. A Salvia darcyi and two Salvia rutilans are
standing outside in pots in a shady spot, alive and well, after being
overwintered in a badly lit hallway. Jolly good show, compared to plants that
will keel over and die if not kept in the brightest light: basils, cucurbits,
okra, morning glories, chufa, jicama or yam bean, cornflower, and all poppy
species that I know.