Heres an answer for garlic, I grow about 300 plants a year and get good results with about 90% of the cloves coming in at 5cm in diameter plus. Season. Garlic takes up to 9 months to mature. Plant in autumn, late March to May, harvest November to December. Clove selection. Plant only the largest cloves, at least the size of your top thumb joint, I have big hands so I plant cloves 2- 2.5 cm across. Its easy to eat the biggest and the best, its better to plant the biggest and the best. Spacing. I plant 15 - 18 cloves per square metre, 25cm apart in rows 25 cm apart. With 30 cm + paths between 4 rows. It's easy to crowd them, and the yield in terms of weight may be much the same, but bigger garlic are a lot more fun and much easier to use in the kitchen. Sunlight. Whilst garlic can tolerate low sun during the winter months it needs 8 hours direct sunlight during the early and late growth stages. So lots of clear sky when it's maturing, September onwards. If your nutrition is right, (and soil acidity is right) then water could be the problem. While not much water is needed in winter, the ground should be kept moist through the season, especially in spring. A shallow watering is best the roots don't go down more than 30 cm max. Once to twice week during the maturing season. We cant control the weather, but avoid flooding (and applications of nutirients) during the final few weeks to lessen the chance of fungus attacks and sprouting. Garlic likes a moderate amount of lime (dolomite), you can rely on the recommended amount at least two weeks before planting and once every three years. Maturity. Look for tops fading in colour, a weakening of the stem near the base and a flattening of the top of the bulb when (gently) exposed Thats a lot and there's a lot more. It's a labour of love and a lifetime. And I'm sure others will have other suggestions, this is just a framework of what has worked for me. Planting at the moment actually. Regarding shallots most of the above also applies but Im not much of an authority. Shorter season length, but most of the above applies. I plant under the same conditions as garlic but only a few dozen and get good results.

- Ken WIlson