Depending on how large a bog you wish to have, you have options. One is to dig 12"-14" deep and smooth in a 1" layer of sand. Then lay plastic or rubber sheeting down. It doesn't have to be as thick as the type used for ponds, but it should be very durable. Perforate the sheeting every couple of feet with an awl or other sturdy pointed tool. That will allow drainage -- the area will retain boggy moisture but not become a pond. Spread your bog soil (good soil mixed with peat or humus compost) For a smaller bog, you can simply ammend existing soil with peat or decomposed coconut fiber compost, then sink individual large tubs into the ground for each planting. Each tub should have a small drainage hole. Making the bog in the lowest part of your property possible helps a lot -- water naturally runs there and doesn't drain as fast as in elevated spots. Digging a depression there, lining it and using a "boggy" soil ammendment (peat, coconut fiber compost) makes the spot even more moisture retentive.

I have no idea about the winter wet but am impressed with a ground cover I bought last year- 2 kinds of Acaena. There is a blue green form, A. saccaticulpula Blue Haze, that is more vigorous and a purple form, A inermis purpureum, that is much less vigorous. They are Stepables so you could see them on their website, which may also have searches for your conditions. They are on level ground in heavy clay so may be good in wet? The blue green one is covered with seed stalks now so I may be able to spread it a lot. It is related to Salad Burnet, which has enormous potential to self-seed, but I'm not worried as it looks like the ground cover I've been wanting to suppress weeds in my beds but be compatible with my roses. I also have Baby Blue Eyes, I believe Isotoma, in a low bed by my driveway that may be very wet in winter and dry in summer, and it does well. It is dormant in the winter. A ground cover that will do very well in wet conditions but not so good for the dry part is Hot Tuna, Houttuynia cordata. It has variegated leaves but goes dormant in winter.

Many spring-flowering bulbs obviously fit the bill, so I'll skip those. AS far as perennials, for early spring foliage and bloom I must recommend Pulmonaria (lungwort). There are various species, of course, but I love those with variegated foliage. And the early flowers are a treat (visually for me and food-wise for early bees)as they turn from blue to pink (or is it the other way round?--no matter--there are always some of each happening at once!). As a sucker for blue-flowering plants, for fall one of my favorites is Plumbago (leadwort), which in my garden began blooming a few weeks ago & is going strong. It would go wonderfully with my yellow fall-blooming crocus located elsewhere in the yard, so I must try to get more & plant them to come up in & among the plumbago. And of course hellebores are a must! I have them blooming sometimes even in February, sometimes under the snow. The foliage is, of course, evergreen, and as it is very sturdy provides nice winter interest. My perennial foxgloves are good too; stay greem a long time and bloom pretty early. Then there is "mystery [or "surprise"] lily"--aka "Naked Ladies" -- Lycoris squamigera. The hardy bulbs put out a lot of robust foliage in the spring (like daffodils on steroids - LOL) and then fade away but the real kicker is the way the fat stems (sans foliage!) come shooting up suddenly in mid- to late August and burst into slow pink fireworks for about a week. I love the silly things; they are ubiquitous here in central Ohio and many of the old farm yards (or older small-town homes)have them. Christmas fern is evergreen, though flattened by snow; ostrich fern sends up edible fiddleheads fairly early and is quite dominant in the shade bed till late (it's still going strong). I have a very large white bleeding heart here when we moved in 3 years ago; I noticed that it keeps self-sowing so have transplanted a number of the young-uns around and these sometimes bloom the first year. It lasts a lot longer in the garden than the wild native in the woods but soon yellows and then disappears when summer arrives (the ostrich fern happily stretches its fronds to fill in the empty space). Sweet woodruff is a wonderful ground cover with a wonderful fragrance & delightful little white flowers in May. I much prefer it to various other alien ground covers like Pachysandra terminalis, periwinkle (vinca vine), English ivy, etc. I do have a bit of our native Pachysandra procumbens (Allegheny spurge), but it spreads much more slowly than the others. That's enough--I'll let others jump in! CK

Probably you have installed your garden untill now, but I just saw your message. Here is my proposed list of plants suitable for windy positions (w), which are very common on the cyclad islands or places with less wind ( ). Trees: Araucaria exelsa (w) Casuarina tenuissima(w) Ceratonia siliqua(w) Chorisia speciosa Eucalyptus camaldulensis(w) Ficus aystralis(w) Ficus nitida Grevillea robusta Hibiscus syriacus(w) Jacaranda mimosaefolia Koelreuteria paniculata(w) Lagerstroemia indica Melia azedarach(w) Morus alba Nerium oleander(w) Olea europaea(w) Pinus halepensis Pinus pinea(w) Punica granatum Quercus ilex(w) Parkinsonia aculeata Schinus molle Sophora japonica(w) Tamarix gallica(w) Palms: Butia capitata(w) Chamaerops excelsa(Trachycarpus)(w) Chamaerops humilis(w) Livistona australis Phoenix canariensis(w) Phoenix dactylifera (w) Whashingtonia filifera Whashingtonia robusta(w) Shrubs: Acacia constricta Atriplex canescens Atriplex hymenelytra Atriplex lentiformis Buddleia davidii Buxus sempervirens Capparis spinosa(w) Carissa grandiflora(w) Caesalpinia pulcherrima(w) Cineraria maritima(w) Cotoneaster horizontalis Cotoneaster lacteus Dodonaea viscosa Eleagnus pungens(w) Euonymus fortunei(w) Feijoa sellowiana Hibiscus rosa-sinensis Hibiscus syriacus(w) Jacobinia gheisbreghtiana Juniperus horizontalis(w) Lagerstroemia indica Lantana camara(w) Lantana sellowiana Laurus nobilis Cestrum nocturnum Ligustrum japonicum(w) Medicago arborea(w) Myoporum laetum(w) Myrtus communis Nerium oleander(w) Phillyrea angustifolia(w) Pistacia lentiscus(w) Pittosporum microphyllum(w) Pittosporum tobira 'nana'(w) Pittosporum tobira(w) Plumbago capensis Punica granatum nana Pyracantha coccinea(w) Raphiolepis delacourii(w) Raphiolepis umbellata(w) Rhamnus alaternus(w) Ruscus acuelatus Spartium junceum(w) Strelitsia reginae Teucrium fruticans Thevetia peruviana Thuja occidentalis(w) Thuja orientalis(w) Tulbaghia Veronica speciosa Viburnum tinus(w) Vitex agnus-castus(w) Yucca aloifolia(w) Yucca filamentosa(w) Yucca gloriosa(w) Yucca elata (w) Yucca schottii (w) Grevillea rosmarinifolia Polygala myrtifolia Asclepias tuberosa Convolvulus cneorum(w) Dimorfotheca calendulacea(w) Felicia pappei(w) Gazania x hybrida Mesembryanthemum(w) Pelargonium zonale(w) Pelargonium peltatum Pelargonium grandiflorum Penstemon Russelia juncea Santolina chamaecyparis(w) Aromatic plants: Aloysia citriodora Lavantula officinalis(w) Melissa officinalis Mentha piperita Origanum majorana(w) Origanum vulgare(w) Pelargonium odoratissimum(w) Rosmarinus officinalis(w) Rosmarinus horizontalis(w) Salvia officinalis(w) Thymus vulgaris(w) Vines: Bignonia (Tecomaria) capensis(w) Bougainvilea glabra Bougainvilea spectabilis Campsis (Bignonia) radicans(w) Hedera canariensis Jasminum azoricum(w) Jasminum grandiflorum Jasminum polyanthum